If you are on I-70, there is literally a Costco gas station about darn near every 300 miles. So on I-70, I just literally went from one costco gas station to the next.
If you can manage, try to pack lunches or have everything you need for lunch. Seemed like everytime we stopped for lunch along the highway, it took about an hour. West of Nashville, the "fast food" places seem to be slow AF.
Trail wise, Moab I can't really speak. When I was out there, we did long routes in the Canyonlands. Was a ton of fun but I'd love to go back and hit wheeling trails.
For Colorado:
If you can't see the trail, get out and look. about 20% of the time I stopped because I couldn't see, there was a cliff or a hole to rollover in or whatever.
MINERAL CREEK TRAIL IS DANGEROUS. Not trail wise, there are bad washouts and the road fails when rigs drive over. I think the bad spot is near the Mickey Breene Mine (So between 550 and the start of poughkeepsie). I think so far this month they've had 4 rollovers due to bad road at that spot. I mention it because every rolled over vehicle has been totaled there. Bad times.
Poughkeepsie Gulch. Run it from Mineral creek (start at north, go south). The actual trail is pretty easy. "The Wall" is a side option trail, you'll hit a sign that says, "left easy, right hard". Right is to the wall. We took the LR3 to the wall but she couldn't make it. But this is legit, one of the best trails there.
Black Bear Pass is best from Ouray/Silverton side (Hwy 550) to Telluride. Once again, one of the best trails there. Not difficult but pay TF attention. A great trail to take your time and enjoy. Try to hit it early. On a Tuesday morning at 8am, we got started. By about 10am we were at the stair steps, we had to wait for a couple of rigs to go down before us. I can't imagine it in the afternoon or weekend. They do get traffic jams.
Ophir is another "take your time" trail. Really great. Its fun from Telluride back to Silverton/Ouray/550. There is a BIG hill climb on a cut out. When you approach, if you see vehicles descending, WAIT. The trail IS NOT wide enough. I know ascending vehicles have right of way, but makes no sense to get your blood pressure up. Once again, not a very difficult trail but fun AF.
The Alpine loop is fun. For the most part, stick to the main trail. On Engineer pass, there is one road, Nellie Creek Trail. Really the only reason to take this trail is if you need a camp spot for the night. Otherwise it dead ends into a hiking trail.
On Cinnamon pass there is an offshoot trail called Carson Ghost town trail. Fun trail up to a pretty complete ghost town. Cool side trail. Also on Cinnamon pass is the American Basin. Cool spot to stop for a moment. But be careful it does get crowded there.
Yankee boy and Governor basin are fun. There are some spots on Governor that I couldn't do in a stock SUV but anything on 33s should be able to do it. Cool mines to check out there.
Imogene is a must-do. Cool to be up top. Approach from either side is cool.
Telluride is a rich California town on island time. Minimal street parking and what there is, is expensive to pay. Unless you need gas, I wouldn't bother stopping there. One cool spot to check out (if you like history) in Telluride is the Telluride Historical Museum. I thought it was cool to check out. If you don't like history, then it is your nightmare. Also close to the start of Imogene Pass in Telluride.
Ouray is ok-ish. Ouray Brewing was meh beer, meh food, and way TF too expensive. Silverton seemed more chill with better bars and cheaper food (not better food, but proportionate). Before entering the area, I recommend loading up on whatever groceries you need. There is a grocery store in Ouray, but closes at like 5pm. The Grocery store in Lake city had frozen burgers, canned beans, and ketchup. Also we stopped at some "breakfast" spot in Lake City. That was pretty miserable. I typically just cook whenever I'm there. Every morning at the breakfast spots in Ouray, they had lines out the door at 7:30am. People were waiting while we were on our way to the trails.
Silverton Conoco gas station on Highway 550 is about the best place to buy fuel. You can get it elsewhere but they are proud of their prices. Before I hit any trail, I made sure I had 3/4 tank of fuel. We did see a number of SxS run out of fuel out there. The LR3 and the Cherokee had decent range so I didn't see any reason to carry extra fuel.
Bearded Wonder Service in Silverton and Timber Ridges Service station in Ouray seem to the be places to get a rig patched back together.