I've used everything in my arsenol (Meguiars, S100, Clearkote) at temperatures in the 30's. No choice when you are a mobile detailer. No problems with any of them.
Relative humidity, I think, is a bigger factor than heat...my $.02. You may find that it being colder, your humidity will drop....You can even have it raining and have low humidity....Like Scott said, I dont think you will have aproblem at all........
I don't see why you would have a problem at that temp. When I lived in Cleveland I washed/detailed my car (including Klasse and carnauba) in the upper 30s. Of course I don't keep my expensive car detailing products in my unheated garage in the winter, so I brought them out from the warm indoors.
Detailing in the cold is easier, except for the discomfort factor. Products like Zymol Carbon *love* to be applied in the cold and are much easier to work with when it's cold.