Hi Pat! Well you've asked the $64,000. question there. Fuel prices really account for a big chunk of a camping trip budget and at these levels it takes some adjusting to make it affordable.
Economically, there are three components to a camping trip:
- the cost of getting there (fuel)
- the cost of staying there (fees)
- the cost of living while there (food, entertainment)
As far as fuel goes, the things you've thought of are probably the best ways to keep fuel cost down. Staying longer at a site and choosing travel destinations that are less far afield are the only real ways, other than actually reducing fuel consumption, to keep the cost down.
The other option is to work on reducing the other two components to account for the rising fuel cost. Choosing campgrounds with lower rates and making other choices to reduce your overall trip cost will help you keep from going broke on the road.
Good luck on the trip!