Sandra, it looks like you'll have the time. San Antonio is the nicest place we have seen in Texas (well Padre Is. is pretty cool too). Note that it can be very hot in southern NM in June.
Santa Fe is our favorite place in NM and we stay at Trailer Ranch. Best to make reservations ahead of time because SF is busy. Don't try to tow a trailer around the Plaza or older parts of the city. The state parks in NM are well kept and priced fairly.
Yosemite is crowded, very crowded, though you will be there earlier in the season. Looks like you are staying at Wawona and will be away from a lot of the turmoil, but the sites may be small (haven't stayed at that CG) and you may be next to tents and others who will not appreciate generators. We tried to run ours when no one was around, but that was pretty hard to do. The drive down to the valley floor will take some time and plan accordingly. But you will be close to the Sequoias. We haven't gone to Hetch Hetchy, but want to because it is supposed to have been as or more beautiful than the Yosemite Valley before a reservoir was built there. Might be worth seeing.