45 days car camping, crazy or doable?

[Traveling Formosan]

I'm planning a 6-8 week trip with my 40lb dog around the western half of the US (all states west of the North Dakota/Texas line) where temperatures may dip below 0 degrees at night. I am working on a photography portfolio trying to get winter photos of the western national parks, as well as night sky photos.

I originally planned to leave much earlier, but a number of things came up, leaving me with the choice to abandon this trip altogether since I will have an assignment abroad come February, or, find a way to make this work before then. Given the planning I have already put into it, I would prefer to go, but also don't want to put either of us at risk.

Basics:
I will mostly be sleeping/hot showering at truck stops and have a 0 degree sleeping bag for dog but only a 23 degree sleeping bag for myself. I have a pile of extra blankets and have several packs of small and large hand warmers to give a boost of heat; I never use the car's (Honda CRV) heating system while sleeping but will probably need to blast the hot air and use the seat warmers before we sleep. While I have done a bit of car sleeping in cold temperatures and both of us were quite toasty even without the added blast of hot air with night temperatures around 20 degrees, I have never tried to tackle temperatures below zero.

I also have a battery (not petrol) powered generator for jumpstarts and cooking should I be out in a park working overnight. Our current sleeping set up: I sleep in the front seat reclined all the way back, and dog is in her hammock in the back seat, though she usually ends up half sleeping on my head. I'm traveling with basic foodstuffs for the duration of the trip, so the back of the car will be filled dog/people food.

*The CRV has AWD and when I took it in for maintenance they said I didn't need dedicated snow tires, but I am seriously questioning this, even if I will only be on major highways the majority of the time.

Is this trip doable if car camping for the duration? What can I do to make this doable safely? What else should I be concerned about?


Thanks in advance for your help!