I think he should be ok as long as he doesn't like sleep in it or anything for a long period of time, depending on if Frank is a baby you might want to work on getting your humidity to like 80% and up I believe is the right number for babies.
Your tort will be a hydrated one tho!
I have a very nice sized yard maybe about 50-75 yards that I have fenced off for there home currently, I have a small group of females that would make your tort very very happy. They have each of there own things, houses to get away from eachother if that's what they want and there own...