I travelled for years full-time with a Collie - well, 2 of them, but only one at a time.
When I had a full sized RV with onboard generator and a/c it was no problem at all.
When I downsized to a van sized camper there was a big difference - hair notwithstanding!...
We managed to get along in the van, mostly because he learned when to stand up and when to go sit on the passenger seat or lay on the bed. It WAS tight quarters with a full-sized dog, especially on rainy days - wet dog on my bed was NOT a good thing!!
With the van I had to be extremely conscious of what I could do when - shopping, laundry, errands all had to be timed for when I could leave him in the van. That meant shopping at 11 PM a lot of the time. That meant not being able to use the deli/butcher/bakery counters and having very limited access to staff if I couldn't find or reach something. Choosing a laundromat where I could either bring him inside with me or see the washers from the van/see the van from the washers. I would have to sit outside someplace cool with the dog while the wash was done.
Sightseeing was another logistical problem - National Parks and a lot of other tourist venues don't allow dogs at all or severely restrict where they can go. I like to visit national historic sites and parks as much as I can.
Truthfully, even though I'd love to have a dog in my life again, I have chosen not to. My choice was lifestyle and size of vehicle or dog. Not saying it can't work but you have to be prepared to deal with the logistics of the dogs needs versus what you want to do.
I make do with having a bunch of 'niece and nephew' pets that I can get my petting/walking time in with!