Dale,
You can move it back and forth from the sun room to the house. Not sure how cold your sun room gets on average, but mine only gets dangerously cold 5-10 days/nights a year. I keep some plants out there year round except for moving them inside the house during extreme cold snaps. Last winter a small fig tree joined them for the first time. It was interesting. The fig tree, which was about 8 inches tall had 3 leaves, it only dropped one leave but it didn't grow any new leaves until April. It did grow roots during that time frame though, occasionally I would see a new root poke out the bottom holes.
The interesting thing is I kept thinking at some point I should move it out to garage to give it some dormancy and I never got around to it, but it started to bud swell the same time as all my trees in the garage were breaking dormancy. The other interesting thing is that this tree is a later ripening variety but it was the first tree to put on a fig, I let it keep the one fig and removed all others from there on.