Me and DW and the kids was on a "campout in the mountains" years ago for Spring Break (Aprilish?) at Mather on the South Rim. That's your only NP campground choice in February.
Even in April it was cold overnight. We felt bad for the tent campers with the fresh snowfall on their camps, while we sat there in warmth and drank coffee.
As I recall (many years ago) it was no hookups, pretty sites, a dump station at the entrance (for when we left). Your February trip will have more chance of snow and cold than WE had in April/May. But snow makes the canyon pretty!
Check that link someone provided. I'll bet you have.
