Down US-95 to Tonopah BLM in September. A short walk to groceries.
Free dumps and potable water at Miller's Rest Area 13 miles west of Tonopah.
There are places to hang out between Reno and Tonopah, but I haven't stayed overnight anywhere in that area.
The problem in September is that south of Tonopah (at 6000+ ft), places like Pahrump, Lake Havasu City, et al. still can hit triple digit highs until mid October. An awkward period without HVAC.
Pahrump had a monthly average high of 100 in Sept 2020. The monthly average low was 64. So quite a cool down after the sun goes down. Comfort depends on personal tolerances. October's average high was in the 80s with average low in the 50s.
I don't about June Lake in September. I was there in late June 2019.