I too have stayed at Haas Lake campground
Also there is a membership Campground in Heartland,MI area..(Waldon Woods?) if you are interested PLEASE PM me and I will arrange for you to contact a member so they can get credit for inviting you. NOTE I have no connection with this campground..But I have a friend who is a member.
I have toured..Do not recall if they are a 2-in one-out place or a Park it and forget it place...But odds are a membership might save bucks.
Places to visit in the area
MARVAC RV Show in NOVI area
Kensington Metro Park
Too many things in Detroit to list (I like good music so Orchestra Hall and the DSO where I have a few folks I know on stage) The Henry Ford (Museum and Greenfield Village) in Dearborn. You can go to HELL, Mi (In the Pinckney Recreation Area) Ann Arbor has lots of interesting stuff. Cranbook,,, Great Lakes Crossing.... Cantebury Village and the Christmas store there...A bit farther is Frankenmuth and the Christmas store there.
The Cascades (in Jackson,MI) and on your way there a store called "The Parlor" (It is not even out of your way)
Want to attend a great concert for next to nothing? The Detroit Symphony does a "Concert in the parks" Series.. I mentioned that Metro Park.. That is one of the venues.
Home is where I park it!