We had booked handicap rooms with roll-in showers at every hotel. All but one got it right. One hotel gave us a handicap room with a tub. When my husband pointed out that he could not hop in and out of the tub, they gave us a shower room, sans handrails. We requested that they move to another hotel at the same price. It paid to have them confirm guaranteed rooms with roll-in showers.
The biggest challenge for us were the bathrooms. None were engineered particularly well for taking showers without flooding the entire room. Issues included shower curtains the weren't long enough, immobile shower heads, too little water pressure, too much water pressure, not enough slope on the floor to move the water into the drain, shower heads pointed in the wrong direction, and no shampoo/soap ledge. I wish I could get Toto, the Japanese toilet manufacturer to re-engineer each room more effectively. It wasn't pleasant to stand in a pool of dirty water while brushing one's teeth at the sink.
Still, we got into the rhythm of packing, unpacking, and putting all of our suitcases back into the car as efficiently as possible. At one hotel parking lot, a woman and her daughter appeared from nowhere and offered to pray for us. That was sweet. Because my husband could not walk places, this was a trip that consisted of driving, visiting friends at their homes, and dining. We did include a brief stop at the Galax Fiddler's Convention and visits to two minor league ballparks. In all cases, we got great handicap parking and seats. On our last day, we donated the shower stool and walker to Goodwill.
The flight home from Dulles seemed daunting. But Enterprise employees arranged to drive us to the airport after we paid for the rental and again, the airport attendant took my husband on a wheelchair all the way to the gate (a vast distance!). Back at SFO, an attendant was waiting for us at the gate and took us to baggage claim. After I had retrieved our suitcases, I took the Park n Fly shuttle to pick up the car. I drove back to the airport to get my husband luggage and we were home about an hour after we landed. Not bad!

Fixed shower head and too short curtains contributed to drainage issue but overall, an acceptable bathroom.

Curtains too short but hand held shower was great!

Fixed shower head facing forward meant major flooding after shower. Handheld shower could not be adjusted.