Rent a 31' class C for a 3-4 day trip to see what you think about staying in it for long periods.
While lots of people spend lots of time traveling in Class C's (some even fulltime) there are some limitations.
Most Class C's don't have a lot of storage space, compared to a Class A or a 5th wheel. Think about where you are going to store your stuff.
A 31' Class C usually doesn't have very much CCC (Cargo Carrying Capacity). That is how much stuff you can put in the RV before exceeding the GVWR (Gross Vehicle Weight Rating). That includes the fresh water tank (8.3 pounds/gallon) and black & gray tanks. Keep in mind that includes the weight of the human passengers and pet(s) as you drive. Here is a link to a weight calculator: Fifth Wheel Weight Calculator
Most people who full time or long time travel put between 1000 and 2000 pounds of stuff in an RV and that doesn't count the water and holding tanks.
You also will probably want to tow a small car or truck. Going for groceries or sightseeing in a 31' rig gets old pretty quick.