We know a couple who travel in their 19' vintage Globetrotter for 9-12 months straight without a problem. They have a cap on the bed of their F-250 and use most of the bed for storage, and they cook outside whenever they can. They see their trailer as simply the means to the full-time existence - the place to eat, sleep, shower, etc. - and a base from which to explore every day. They've done it for years, traveling from Novia Scotia to Florida to California to Alaska and everywhere in between, and seem quite happy with the size. They have a bigger trailer docked at an Airstream park for the times they're not traveling but like the smaller trailer for being on the road.
Ben & Molly (but Ben never types, so it's always Molly