towing from calais to benidorm in december.

please help,this december we are towing our caravan to benidorm to spend christmas there for 5 weeks.This will be our 1st trip abroad with a caravan and i am concerned with which route to take as i want to avoid paris if possible.Is it realistic to be able to do it in 3 days.Also is it safe for car and caravan to have over night stops at motorway hotels/motels.