We went from truck and trailer (23 foot box) to our 31 foot Winnie this past spring and we love it. Like others have said, your total travel length will be less if you don't tow a dinghy (we don't). In fact there have been a couple of times where I'm signaling to move over a lane and the kind driver in the other lane flashed me to show I was clear, in a much shorter distance than I thought!
The first time you have to use the restroom on the road or stop at your destination and don't have to unhitch you will feel 110% confident in your decision :) Congratulations!
Editing to add something that came to mind - we watched some RV Driving videos made by the folks at LazyDays, they're aimed at class A's, but we still found them helpful:
Drivers Confidence Courses