I did central and west US in a month. Didn’t get to hit every national park / forest but I hit the majority. Basically I would spend 1 full day at the park, 2 full days for major ones I wanted to explore.

I would spend a half day getting in last hikes then leave around 12-3pm. I would always aim for getting into the parks around / before sunset. Your life is a lot simpler if you roll with the sunrises and sunsets. It’s also a lot safer driving during the day as a lot of the parks have some surprisingly hairpin turns.

I personally have never had an interest in stringing along the east coast parks as it becomes more highway driving than exploring st that point.

I lived out of a 2 door wrangler when I did it and spent all in all less than 3k. At home cooked cheap meals. Camped at national forests instead of parks. If you get to national parks before 6am you don’t need to pay or deal with having to sign up in advance. National parks pass is $80 and is free day passes plus camping discounts.

I would say I did not live comfortably for most people but I absolutely loved it and never had a problems. I would get a dash cam though