Since it's a long drive, is it possible to double up your 3 day weekends in a back to back fashion? Take 2 extra days off also?
Then package it all up over say Labor Day weekend, assuming that your Monday is a holiday?
This is of course if the area you plan to go is not a major holiday weekend camping fiasco.
2 travel days and 7 days of scouting maximizes the time and cuts down on the fuel expenses and wasted windshield time.
We did this quite a few years back for Wyoming and it worked out very well for us.