A really good quality Carnauba Wax will flash harden within several hours, but won’t completely ‘cure’ for 72 to 96 hours (3 to 4 days) depending on temperature and humidity. I believe this to be true as my details look much deeper/wetter since I’ve been waiting 4 to 5 days between applications. I certainly wouldn’t put sealer over wax that’s less than 4 days old. A pain in the @$$ to say the least, but I’m pretty anal about doing the best job possible, and toss in my OCD – and a refusal to take the med’s ;-) ... and the car has depth of shine like nothing else.
I don’t think you should attempt applying any product below 45/50 degrees, but the temperature is only my opinion, and I’m sure there are more knowledgeable people on this site with a more educated answer. Looking forward to seeing what temperature they say is the cut-off for applying wax.