I think if I was going to refrigerate my waxes I'd pick a temperature in the 45F/7C to 55F/13C range. If you have control over humidity I'd aim for <70% and >45%.
For non-refrigerated storage I think the range from 40F/4C to 75F/24C is probably fine for almost all waxes. You can get by with higher storage temps but it isn't ideal. For high end waxes I would try to keep them below 65F if at all possible. As with most detailing chemicals you want to avoid rapid temperature swings, intense light and temperatures below freezing or very warm/hot.
My own waxes are stored in an unheated part of our basement where temps stay in the 55F/13C to 65F/18C range year round. I try to order waxes in the spring or fall to avoid potentially high temperatures in shipping.