We're going on our 7th year at a seasonal site. Couple things you might want to consider.
Buy a good surge protector if you don't already have one.
See if there is a local LP place that will take care of your LP needs. We use more LP in the spring and fall with the furnace going and got tired of refilling our 30 lb tanks. Found a place that rented us a 100 lb tank for $1 a year and charges alot less than the campground or local gas stations per fill. They even did all the hookup work for free.
See if the campground sells firewood in large quantities instead of the small bundles which are fine for overnight campers. We can buy a front end loader bucket full for $25.
Park the tires on a couple roof shingles that are laid down over pressure treated wood.
Come fall be ready to mouse proof the heck out of your camper by sealing up the smallest hole or void in the underbelly.