For my routine painting, I set up at the kitchen table with my mobile painting tray (the kind with sockets for paints). It works wonderfully and set up is fast enough that I can make use of little 15 minute blocks of time to paint.
For gaming, my father-in-law found and bought me a small used trailer home, the little ones often used as offices by contractors on large work sites. (He is an absolutely master of the used/for trade market!) We got it wired for electricty and water and had a septic tank put in, so it is entitely self contained gaming space! I will have ample room for both a 6×4 gaming table and a separate space for large projects, like terrain building.