I think if you've got a fairly stable "cellar" you can make do even if the temps aren't ideal.
My "cellar" is a back closet in the house, next to a large steel safe. Temps typically hover around 72o in the summer, ±1o or so. Winter it's usually 62o with the same variance. I've had very nice results, so I've added to my stock.
I'm sure more ideal conditions would result in a better beer in the end, but I still think it's worth it.