To make a VFT go dormant in places in the US where it gets too cold to leave them outside all year all you should need to do is place it about 2 inches from the glass of the window. The night chill on your window should make a nice little microclimate that gets cold enough to make it go into at least a light dormancy every Winter and that is all a VFT really needs. VFTs don't really need temperatures much below 50 F to go dormant, especially red forms. Refrigerator dormancies or garage dormancies are overkill. The VFTs can still photosynthesize all Winterlong in a windowsill but not in a refrigerator or garage.
There are VFT growers in CA who grow VFTs in greenhouses and their night time temperatures sometimes don't even drop below 50 F during the Winter. They often have daytime temperatures that soar into the 80s F in their greenhouses and yet their VFTs still go dormant every Winter just like they are supposed to.