Almost any commercial campground will have full hook ups and offer weekly and monthly rates. Away from destination areas, you will have little problem finding a space. However, in popular vacation areas and snow bird destinations during season, you may have to improvise such as accepting partial hook ups until a full hook up site opens, or stay at a less convenient campground.
You will find difficulty finding open campgrounds, especially with water available, in the northern part of the country during winter.
There are available campground directories and apps to help you find campgrounds.