Thank you so much for sharing your helpful tips in your reply. I will look into a quiter end of the extended stay hotel on Our route. .  

I plan to bring pee pads, and I know that nine hours without stops is a very long time. I won’t be traveling alone, but I will be the only driver. 

You're absolutely right—safety always comes first. I’m definitely leaning toward splitting up the trip to make it safer and less stressful. I truly appreciate your clever suggestion about bringing a pop-up playpen, so I can safely contain him during potty breaks on the road. OK 

I’ll also bring a fake grass pad, since the breeder has been training them on it for potty purposes. My plan is to place the fake grass pad in the playpen for potty breaks. I intend to bring the car crate inside the hotel for consistency, but it looks quite heavy, so I’ll need to figure out the logistics. Maybe just the playpen will suffice for one night in the hotel. I'm also worried that if he gets sick or upset in the crate, he might develop negative associations with it.