Camping in a tent?
Just the two of you?
Can you remove your rear seats?
1. AOPA used to list in its airport guide if camping was allowed on the field.
2. Madeline Island (4R5) permits camping next to your airplane. You can walk from the airport to the town. There is a ferry from the island to Bayfield, which is also an interesting place to walk around.
3. If you have bicycles and your rear seat is removed you can take them with you. I use Bike Fridays, if I am going to do mostly road touring.
If I am going to ride gravel trails, I take regular bikes with 2 inch wide tires. On those bikes, I remove the pedals, the wheels, the seat and seat post (after marking the height with black electrical tape). I then turn the bike upside down and wrap the chain with a large dark colored towel. I then place each bike into the luggage area through the front door, standing the bike on its handle bars.
I then carefully pack the rest of the parts into the airplane.
Note: I have a handle bar bag on each bike. I place the pedals in the bags. That way I can use the pedals to propel the bike after I get the bikes put back together. Not fun to find them on the hanger floor when I have returned after the trip.
On Madeline Island, there also is a state park you can camp in, but you have to ride there. One advantage of the state park is showers.
There are probably other places you could fly to, but I think Madeline meets your stated requirement best, if you do not carry bikes and don't mind walking about two miles to the town of La Pointe, Wisconsin.