When I started to read this thread, I thought "He needs to go to a National Park." What else would a retired NP ranger suggest? I am glad to see that others are ahead of me on that. The advantages have already been listed and they are real. I think that I would also look carefully at Yosemite. It offers a good base camp situation and resupply, along with a great variety of trails, many of which are unfrequented and remote.

I would also suggest you consider Isle Royale. It is an unknown gem (or gym, as the case may be). Extremely remote, it is usually the least visited of the stateside national parks. It is definitely fabulous country. I was there for a project two decades ago, and getting back there for a recreational trip is on my bucket list. You might even considering asking about volunteer opportunities for part of your visit (I have no idea about the present volunteer opportunities). In general, volunteering can be (but not always) a very interesting and unique experience. You can get places you would never reach otherwise, for instance. Just a thought.....

Consider Great Smokies or Shenandoah as well, but if you want to get away, Isle Royale is head and shoulders above everything else, while still providing you a base for resupply.