Success! Thank you all!
What finally worked was a crescent wrench opened all the way and using my foot to push it down to loosen the nut. I could get that to stay toward the base of the nut. I did get a socket which needed a bigger handle. This all was too heavy to stay on well. I had to use my foot since my arms/hands were just not strong enough.
They got the tire sealed onto the rim, but warned it might not last real long. We just needed to get it to a storage place. Sister will be able to come here in a couple months and stay long enough to get the rig sold etc.
So, sometimes those useless crescent wrenches actually are useful. :)