Next day should be OK. Or you can try a hair dryer but if you do make sure the paper is completely dry or you'll ruin your negative. Otherwise do what I do, put a piece of mylar between the negative and the paper.
Keeping qualities really depends on the paper. Paper is the bane of Alternative Processes. I've coated cyanotype I could use a month later on one paper, and some I could not use the next day on others.
On dry coated paper yellow is great, green OK, as long as the surface hasn't truned blue or blue/green you should be fine.
The best advice is get in the darkroom and trycoating your paper and see what happens.