Your trip is certainly possible, but it is very heavy on the driving. I do wonder based on your previous experience you're going to end up disappointed.

While we're certainly getting closer to the end of the covid tunnel, it's perhaps a bit premature to say that covid is fading. It's great that you have been vaccinated, but at this point only 10 percent of the country has, and while some states are lifting all restrictions, they are doing so despite the harsh warnings from scientists.

My point is not that you shouldn't make this trip, more that I think you may still find many of the same issues that made your November trip a disappointment are still in place. Obviously, it's state by state, but many places still have restaurant restrictions in place - and even if it's not legally required, there are businesses voluntarily following health guidelines. Perhaps more importantly, generally speaking people are still less than interested in fully engaging with strangers. To that end, perhaps skipping California this time around, spending more time in the many National Parks between StL and Vegas would not just mean less driving, but it could mean more a more enjoyable experience overall?