I've not done any cruising, yet, but have lived on my 57footer narrowboat, and I would say that given time, you could find a smaller boat [52-4 ft] that is nicely fitted out and well laid out, easier to manoevre and cosy enough.
I would prefer a single dinette [desk] , again making the thing more spacious, but with high seating which is more storage and good view out window, my cat sits high and looks out the open window, popping in and out as desired.
If you don't have a pumpout that gives you more storage, a smaller bed [3ft makes boat less "narrow", and ideally [for me I would have a very swish modern walkthough shower/loo. The cassette thing does create a problem, mine only lasts seven days,[thetford Excellence] if I am on board full time, and I have emergency dry loo of a primitive design. I like the Excellence 'cos it's a nice height, but ideally I would have two!
Once I have cruised the whole network, expect to settle either North or South, but I would still like to have proper boat again [dutch style], but that is in about eight year, when I am getting on a bit [hitting 80]. I don't worry too muh about emergency ill health, just cope with it when it comes along. You can always ring one of the emergency services or you will post on here ad someone will sort you out short term. You're never far from ciilization.