If you're limited by not having a basement, attic, or a cold window sill, I think your best bet would be the afore-mentioned fridge method, espoused by Scottychaos. A couple winters ago I had my VFT's between the storm and inner windows of the kitchen. That wasn't working out too well, so I tried a screened in porch. That was okay until we had a cold snap. The soil froze. Horrified, I put the 2 two inch pots in the butter keeper, where they resided for the rest of December and January. In February, I brought them to work with me (environmental laboratory) and had them in a sample fridge. In March I put them on a cold and draft window sill, in my work area. In April I put them outside, where they soon flowered. Then they promptly got gnawed by critters.... but that's another legacy. And now I have them in our cold attic, by the window sill, where they just go dormant and wake up on their own.
Cute cats, BTW. Got any Maine Coon kittens?