Telescope Peak is an outstanding alternative to the Sierra. It may be 100+ on the valley floor, but the trail will be very comfortable. Any vehicle can make it as far as the charcoal kilns. It's not a big deal to start hiking from there. The road continuing to Mahogany Flat can be 4-wd depending on conditions. The views are world class with Mt Whitney to the west and Badwater to the east. The elevation difference (Telescope at 11,043' and Badwater at -282') for two places that close together is one of the largest on earth. If you have never hiked Telescope, you owe it to yourself to go.
I hiked Telescope Peak about 2 years ago. The road to Mahogany Flat is very rough, but I was able to do it in a 2WD Ford Ranger. That is definitely not a spot to get stuck.
There is a spotty cell signal (Vzw) near the trailhead, but none at the summit.
As you mention, the weather was ideal starting and staying at altitude.
You can even see Mt San Gorgonio and Mt Charleston in Nevada from the summit.
edit: Looks like White Mountain is closed and the gate is closed past the charcoal kilns before Telescope Peak trailhead.