Sleepy Hollow is close, but can be busy. There are lots of fields and trails to walk with the dogs.
Lake Hudson Rec Area south of Jackson is a nice and generally not crowded park. Semi rustic, meaning it has electric (bring extra extension cords as the boxes can be a way away) but a well pump and pit toilets.
Holly early in the year should be relatively open.
Otherwise, as you know, the LP parks fill quickly! Good luck!
Damned fine of you to share! Not sure I wouldn't keep that little nugget under wraps - thank you!!My absolute favorite time to camp in Michigan is the weekend following labor day. Any campground (mostly state campgrounds) that I've been to are COMPLETELY empty! It's heavenly. Last year we were at Burt lake that weekend, and had maybe a dozen sites full... Out of hundreds! Our labs had a blast, they have a dog friendly beach area.