We too were in NW Montana last week, not with our Airstream but with our Harleys. Did our paths cross at a gas station pump? I gave a thumbs up and said "hi" to a couple with a truck/Airstream set up that looked like yours....(I know, a silver truck w/silver Airstream = pretty common!)
We were also told the east side of the park was completely closed due to it being part of the Indian reservation and Covid and the snow amounts.
We did speak to some folks in Whitefish that had gone into the park 7/3 (in the rain) and they were able to enter on the west side an go on the road to the sun - but only to Avalanche Creek where they had to turn around. We tried to go on 7/4 very early in the morning to do the same - and were hopeful as they were letting people in the gate for free. But we were only able to go about 2-3 miles and were turned around at the base of Lake MacDonald & the Apgar Visitor Center as the "park was already full for the day". They said they would let people in as people left but it would be a 3-4 hour wait & you would just have to chance your timing. Pretty disappointed...no wonder they let us in for free! What we did see was gorgeous - we'll be back!