True, it's a pity not more hire firms allows you to leave the boat at one end so that you don't have to go back in you own tracks, but I suppose that is part of the parcel and we'll not be the only ones that have done that so it can't be that bad.
A lot of firms are located out in the skits, aye, but taking a minicab doesn't have to be outragously expensive either. I once took a cab from Heathrow to Ipswich (the worst day ever - a delayed flight and a train strike so that was the only option). It cost me £140. A lot of money (work paid), but split among a group it wouldn't have been that bad.