You won't need to run ac except if the temp goes 100F+- depending on your tolerance and then probably only if you are trying to sleep in the late afternoon during a duststorm.
Most of the time you can just open up and let the breeze in.
Dust is a given but highly overhyped ( except for last year and just about every year before!LOL
~Wendell~

We only used the air conditioning for about 1/2 hour total last year in our Class C. Yes - it gets warm/hot but close the windows on the windy side - and open the opposite side for some air. The RV will get dusty - no stopping that. We got home and used a leaf blower first, then shop vac, then Dyson, then wiped it all down from top to bottom on the inside. Took 3 days of constant work and still found dust in the vents when we turned on the heat in January during a trip. We didn't cover furniture as some said they have but kept clothes, camera's etc in plastic totes to help minimize the dust. Also took a complete change of clothes in zip lock bags just for when we were on our way home. Spent the first night in a small RV park before Reno and enjoyed the shower there. Made for an easier drive back to Calif foothills when we were clean. When it is hot during the day, find some shade, drink lots of water and try to stay out of the sun. It is bearable that way. Also, tried to use porta-potties as much as we could but still with 4 people, we did flag down the pump guy once for a clean out. May have made it through the week but didn't want to risk it. You will have fun. This will be our second year and we are counting the days.

if you are spending the night before hitting the playa, I would suggest Fernly. there is not much in Gerlach, and there will be so many other BLM folks, burners, yada yada, that you might find lines and wait times long.. but it could be a heck of a story..

good luck!

and yes during the heat of the day, if the dust is not blowing too much, I prefer to sit in the shade right outside my RV door, but then, I bring 3 popup shade structures to keep the front of my RV comfortable for visitors. etc. and I put out the astro truf.. and the cooler with cold beer..... hey, why are we not there yet!!

I also rented a Class C last year. Ran the AC maybe 15min a day (if that), and then mostly during the big dust storm on Saturday. Only time I ran the AC was when I was doing some food prep inside during the heat of the afternoon. Other times, I would just run a 12v fan inside so I wouldn't need to crank the generator. I didnt have any problem with closed windows and running the AC. I do recommend keeping the AC filter clean... wash the foam filter (if you have one) once every couple of days.

Regarding dust, like everyone says, it will get dusty inside. What I did was

1. taped household air filters on a few windows so I could keep a window open and not have to worry about excessive dust inside.
2. I got some old sheets and covered the couches and used another to over by bed/sheets/blanket. These worked out nice, but after a while you do kinda miss the dust :-)
3. The RV rental place also puts down plastic carpet runners, which also helped keep the place clean.
4. Lastly, have a carpet or welcome mat by your front steps, and try to knock off dust before going inside. Taking off your shoes works like for a day, then you just dont care anymore.

For post playa cleanup, 2 things are a MUST

1. Get the exterior washed at the truck wash at the Fernly I80 exit. Best $35 ever spent!
2. DO NOT wet down dust inside. Instead, get those 3M anti-static dust rags (sold in most stores). They work like friggin magic with playa dust. The interior cleanup took only a couple of hours, and it really looked imaculate for the rental return

One thing to keep in mind is the heat at BM is different then Austin's humid weather. I'm not sure how familar you are with desert weather but 100F in Austin is like 113F at BM.

At night the temperature is definitely jacket weather. It gets in the 40s-50s sometimes. Be prepared for any type of weather.

I don't know anything about opening the windows in my RV during the day. I always keep them closed. But then again I have a swamp cooler and not an AC. Plus I have sheets over my windows to filter out the dust. I sometimes open the windows and the lids at night.