El Paso to Casa Grande is about 390 miles so if El Paso gets completed by then, staying the night at a strategic location where you can charge in between those superchargers could make the trip work without too much hassle and even with some hassle it could definitely be worth it if it saves a ton of time/miles.
I know that area is sparsely populated so it's not easy, but looking at plugshare, it looks like you could park your car overnight at the KOA campground in Lordsburg, NM and walk to a nearby hotel and your car should be charged overnight. Definitely call ahead to be sure they are open if you are trying to pull off something like that.