Regulations have changed over time. When I started camping with dogs, the dogs slept outside the tent, one on the door flap and one at the rear. Hearing their occasional soft growls at imagined dangers they were keeping from the tent was part of the experience. Now, that would be against the rules in most campgrounds. Dogs must be inside the tent or in a vehicle at night.
Many campgrounds also limit the number of dogs per campsite.
If you are a multiple-dog family, this is something to check into when you are making preparations.