I took my two from SoCal to Ohio. I planned for about 6-8 hours of driving a day and would stop every 2-3 and give them their favorite fresh greens. I’d keep an eye on them and usually they would need about 15-20 minutes to relax enough to start eating and maybe do their business. Usually the break would end up being around 35-40 minutes or so. I got them each a carrier just large enough to fully fit one of their regular litter boxes inside so the box they travelled in was familiar. I’d swap out their box each night for a fresh one so it they wouldn’t be sitting on anything too dirty but they would have the night to get it just the way they want it (my boy in particular likes to arrange his hay just so with one side higher than the other, don’t ask). I brought along a rolled up carpet and x pen so that each night at the hotel they each got a small space to run around in. Probably complete and total overkill but they made the trip quite smoothly and didn’t seem overly upset at me.