Personally I like the river Soar, not sure if you could do Foxton and Back in a week, but it might be worth considering. The route should have a far bit of interest.
Ron
Route from http://www.canalplan.org.uk
Preferred route from Sawley Marina to Sawley Marina via Foxton Bottom Lock
River Trent (Western End)
From Sawley Marina to:
Trent Junction
Junction of River Trent, Grand Union Leicester Section and Erewash Canal 1 mile, 1¼ flg, 1 lock
Grand Union Canal (Leicester Section - River Soar Navigation)
From Trent Junction to:
Soar Mouth 0 miles, ½ flg, 0 locks
Normanton-on-Soar Wharf 6 miles, 5½ flg, 5 locks
Loughborough Branch Junction 2 miles, 3¼ flg, 2 locks
Barrow upon Soar Junction
Between Barrow upon Soar road bridge and Barrow Deep Lock No 51 3 miles, 5¼ flg, 1 lock
Barrow upon Soar
Bridge 28. Barrow upon Soar village a quarter of a mile north 0 miles, 3¼ flg, 1 lock
Mountsorrel Railway Bridge
Also known as 1860 Bridge 1 mile, 3¼ flg, 0 locks
Sileby Road Bridge No 24 0 miles, 1 flg, 0 locks
Sileby Changline Bridge 0 miles, 5½ flg, 1 lock
Junction Lock No 47 2 miles, 5½ flg, 2 locks
Syston
Bridge No 19 0 miles, 7 flg, 1 lock
Thurmaston Lock No 46
Thurmaston on east bank 1 mile, 1¾ flg, 0 locks
Memory Lane Wharf 3 miles, 3½ flg, 4 locks
Soar Lane Bridge 0 miles, 7¾ flg, 1 lock
Leicester
Moorings for city between Newarke and West Bridges 0 miles, 4½ flg, 0 locks
Great Central Railway Bridge
Now the Great Central Way - Route No 6 of the Sustrans National Cycleway 2 miles, 3½ flg, 3 locks
River Soar Junction
Junction of GU Leicester Section and River Soar Navigation 0 miles, ½ flg, 0 locks
Grand Union Canal (Leicester Section - Leicestershire and Northamptonshire Union Canal)
From River Soar Junction to:
Blaby Bridge No 98
Blaby half a mile south 2 miles, 3 flg, 4 locks
South Wigston
Crow Mill Bridge No 92. South Wigston on north bank 1 mile, 4¾ flg, 2 locks
Kilby Bridge No 87
A50 1 mile, 5 flg, 3 locks
Newton Harcourt
Newton Church Bridge No 80. Newton Harcourt to the north 2 miles, 2 flg, 7 locks
Great Glen
Station Bridge No 77. Great Glen village 1 mile north 0 miles, 6¾ flg, 0 locks
Fleckney Bridge No 73
Fleckney half a mile west 2 miles, 1½ flg, 5 locks
Saddington Tunnel (Northwest end) 0 miles, 2¼ flg, 0 locks
Saddington Tunnel (Southeast end) 0 miles, 4½ flg, 0 locks
Smeeton Westerby
Smeeton Hills Bridge No 70. Smeeton Westerby half a mile north 1 mile, 2 flg, 0 locks
Gumley
Bridge No 69. Gumley village three-quarters of a mile south 0 miles, 1 flg, 0 locks
Foxton Junction
Junction of Grand Union Market Harborough Branch with Leicester Section 2 miles, 2½ flg, 0 locks
Grand Union Canal (Leicester Section - Old Grand Union)
From Foxton Junction to:
Foxton Bottom Lock 0 miles, 0 flg, 0 locks
Turn round here
Foxton Junction
Junction of Grand Union Market Harborough Branch with Leicester Section 0 miles, 0 flg, 0 locks
Grand Union Canal (Leicester Section - Leicestershire and Northamptonshire Union Canal)
From Foxton Junction to:
Gumley
Bridge No 69. Gumley village three-quarters of a mile south 2 miles, 2½ flg, 0 locks
Smeeton Westerby
Smeeton Hills Bridge No 70. Smeeton Westerby half a mile north 0 miles, 1 flg, 0 locks
Saddington Tunnel (Southeast end) 1 mile, 2 flg, 0 locks
Saddington Tunnel (Northwest end) 0 miles, 4½ flg, 0 locks
Fleckney Bridge No 73
Fleckney half a mile west 0 miles, 2¼ flg, 0 locks
Great Glen
Station Bridge No 77. Great Glen village 1 mile north 2 miles, 1½ flg, 5 locks
Newton Harcourt
Newton Church Bridge No 80. Newton Harcourt to the north 0 miles, 6¾ flg, 0 locks
Kilby Bridge No 87
A50 2 miles, 2 flg, 7 locks
South Wigston
Crow Mill Bridge No 92. South Wigston on north bank 1 mile, 5 flg, 3 locks
Blaby Bridge No 98
Blaby half a mile south 1 mile, 4¾ flg, 2 locks
River Soar Junction
Junction of GU Leicester Section and River Soar Navigation 2 miles, 3 flg, 4 locks
Grand Union Canal (Leicester Section - River Soar Navigation)
From River Soar Junction to:
Great Central Railway Bridge
Now the Great Central Way - Route No 6 of the Sustrans National Cycleway 0 miles, ½ flg, 0 locks
Leicester
Moorings for city between Newarke and West Bridges 2 miles, 3½ flg, 3 locks
Soar Lane Bridge 0 miles, 4½ flg, 0 locks
Memory Lane Wharf 0 miles, 7¾ flg, 1 lock
Thurmaston Lock No 46
Thurmaston on east bank 3 miles, 3½ flg, 3 locks
Syston
Bridge No 19 1 mile, 1¾ flg, 1 lock
Junction Lock No 47 0 miles, 7 flg, 0 locks
Sileby Changline Bridge 2 miles, 5½ flg, 3 locks
Sileby Road Bridge No 24 0 miles, 5½ flg, 1 lock
Mountsorrel Railway Bridge
Also known as 1860 Bridge 0 miles, 1 flg, 0 locks
Barrow upon Soar
Bridge 28. Barrow upon Soar village a quarter of a mile north 1 mile, 3¼ flg, 0 locks
Barrow upon Soar Junction
Between Barrow upon Soar road bridge and Barrow Deep Lock No 51 0 miles, 3¼ flg, 1 lock
Loughborough Branch Junction 3 miles, 5¼ flg, 1 lock
Normanton-on-Soar Wharf 2 miles, 3¼ flg, 2 locks
Soar Mouth 6 miles, 5½ flg, 5 locks
Trent Junction
Junction of River Trent, Grand Union Leicester Section and Erewash Canal 0 miles, ½ flg, 0 locks
River Trent (Western End)
From Trent Junction to:
Sawley Marina 1 mile, 1¼ flg, 1 lock
Total distance is 88 miles, 3¾ flg and 86 locks. There are at least 2 tunnels.
This is made up of 0 miles, ¼ furlongs of narrow canals; 30 miles, 5¾ furlongs of broad canals; 57 miles, 5¾ furlongs of small rivers; 44 broad locks.
This will take 47 hours, 32 minutes which is 6 days, 5 hours and 32 minutes at 7 hours per day. For calculation purposes this is taken as 7 days.
Overnight stopping places
This is calculated based on 7 full days travelling.
Each full day will be approximately 6 hours and 47 minutes travelling.
First day of trip
On the Grand Union Canal (Leicester Section - River Soar Navigation), at Meadow Farm Marina, Barrow-upon-Soar (a third of the way between Barrow upon Soar and Mountsorrel Railway Bridge)
14 miles, 7¾ flg and 10 locks.
Second day of trip
On the Grand Union Canal (Leicester Section - River Soar Navigation), at Freestone Bridge No 106
13 miles, 5¾ flg and 12 locks.
Third day of trip
On the Grand Union Canal (Leicester Section - Leicestershire and Northamptonshire Union Canal), at Newton Harcourt
8 miles, 4¾ flg and 17 locks.
Fourth day of trip
On the Grand Union Canal (Leicester Section - Leicestershire and Northamptonshire Union Canal), at Great Glen
14 miles, 2 flg and 10 locks.
Fifth day of trip
On the Grand Union Canal (Leicester Section - River Soar Navigation), at Aylestone Mill Lock No 39 (just past Great Central Railway Bridge )
9 miles, 3¼ flg and 16 locks.
Sixth day of trip
On the Grand Union Canal (Leicester Section - River Soar Navigation), at Meadow Farm Marina, Barrow-upon-Soar (two thirds of the way between Mountsorrel Railway Bridge and Barrow upon Soar)
13 miles, 1 flg and 12 locks.
Seventh day of trip
On the River Trent (Western End), at Sawley Marina
15 miles, 3 flg and 10 locks.