I'm generally happy with my little 31ft boat to live on, there's more than enough living space for one person with that mindset.
I've considered looking for an ex-working boat with a hold so I can get back into hobbies/projects that need storage space, which is one major limitation of a small boat. And also because they're lovely things in their own right. Would have similar or less cabin.
I do think 31ft, and possibly 38ft, might be too small for two people long-term. Not enough room to be apart and do separate things sometimes. A friend visiting me for a few days was ok but a bit short on privacy.