Thanks for the replies. I don't know why this trip has me on edge. It's not like I'm an inexperienced traveler. Heck in the spring of 2019 I went to Europe for the first time as a birthday present to myself for 3 weeks and had no such edginess. Maybe it's because since then I've had 8 trips ranging from the final planning stages to three actually being booked end up being canceled and I'm just waiting for the other shoe to drop. Might be because I haven't connected in DEN since 2006(!) so it's essentially a new airport to me (then again so was LHR, LIS, taking Eurostar from London to Paris and taking other trains in France that I somehow survived). Anyhow I've ruled out ORD because when I first looked I thought it said 2 hours and when I double checked the times right before posting I caught my error but decided to leave it as an option. I see today's flight left about 20 minutes late but still arrived early albeit at A76. I'm just going to roll with it and if I miss the connection United will have to get me to Phoenix somehow -- hopefully in F and not in a middle seat in the back of the bus!
I do have one more question I forgot to ask before. How common are water bottle filling stations in DEN? I always carry granola bars or something similar to eat on the plane but I'll probably need to top off my water bottle since I doubt there will be much of a beverage service during the flight.
Thanks again for the advice and man I can't wait to be traveling again!