Well, we drove cross-country from NY to Cali. I kept the snakes in pillowcases in a large rubbermaid. They made it through just fine.We stayed at a Super 8 in IL (lady said that if we brought the snakes in, she would play dumb.) Then a Best Western in Kearney NE that was fine with pets and the desk clerk said that it was no big deal. Then we stayed in a motel in Salt Lake City ,UT that I forget the name of,and we just brought them in the tote; no worries, we were never out of the room while they were with us. And in Vacaville CA we stayed in a rundown motel and did the same.
All places were relatively warm, and we just made sure that the tempsstayed around 70 ish for the snakes, which we kept in the bathrooms out of the flow if AC that was always by our bed. In hindsight, a heatpad would be a good idea, but it was pretty warm travelling in summer (especially in Utah!)
Best Westerns are generally very nice, and pet friendly; but they do have executive type hotels that cater to office-people and aren't pet-friendly; we went to one, and they referred us to the pet-friendly BW down the street (in kearney NE)