So with all that here's a rundown. You being 47 does not make the risk appreciably different from 27 or from 57 based on what's out there.
1. If this country were being responsible, this trip would not be allowed from a public health point of view. There are too many states in real deep trouble right now - probably 25 should be back on stay at home orders and 10 are approaching hospital capacity crises today, but because our political system is irresponsible we can't do that. No state has cracked the code of "reopening while there are still cases out there" and tracing is failing because the systems are so poorly built and there's no national organization or help. States where you are traveling need to shut down until they Figure out what the Hell is going on.
But, since they are open, you're allowed to. There are a couple legal matters you should consider in advance. First, what happens if a partial travel shutdown does occur while you are there? Second, the state of Illinois could impose a 14 day quarantine on travelers coming from those states, and that could appear while you are there so you might have no warning beforehand. If that were to happen, are you ok with it costing a full week of school? Frankly, I'm surprised it hasn't been put in place already. New York has done it, but they have to specifically worry about people traveling from Florida - maybe Illinois needs to identify some cases directly linked to travel before they do it, but it could absolutely happen.
2. The odds of someone in your family being exposed are high. You've listed the locations - hotels, restaurants even outdoors, planes, gas stations, hikes. Many will be short passes, but some won't, and even ones outdoors can have some risk, particularly restaurants since you have servers and other guests around. Whether that person receives a dose that is enough to get them sick depends on things mostly out of your control, including what safety precautions others take and basically luck (is the person near you on the plane sick, is the person in hotel line next to you sick). Whether the hotel in Vegas is the biggest risk probably depends on what the various outbreaks do over the next month, I'm not sure that's a far greater risk than any other hotel as long as you're not on the gambling floor. Flight risk is nonzero, depends on where people sit, but if you skip the flight and drive you have food stops and bathroom breaks that are all places where other people will be. So, you're likely to be exposed, and the chances of actually getting sick even if you do everything right are probably moderate, but difficult to estimate precisely, and unless Vegas explodes in cases in the next month, there's no spot you can skip that is going to dramatically lower the risk of exposure.
3. If someone in your family does get sick, with no pre-existing conditions, the chances of them dying are very low, probably 1 in 1000 or so give or take. So while you will likely survive, this probably does significantly raise the chances of someone dying on this trip compared to a trip in a normal year.
4. While the chances of dying are very low, the chances of someone getting very sick and perhaps suffering a permanent issue are noticeably higher. Still low, but definitely nonnegligible. The hospitalization rate has stayed pretty constant everywhere at 5-10% of the people getting it. Probably lower for your health group, but still several percent. The only thing that has reduced that rate is states lying about their data. That means someone could, reasonably, permanently lose their sense of smell or have permanent lung or kidney damage from this trip, and that is not an issue unlikely enough to be ignored. For example, we learned yesterday that Rudy Gobert of the Jazz still does not have his sense of smell back nearly 4 months after being infected, and he's an NBA athlete.
I can't tell you what to do because my personal risk tolerance is different and my personal health situation colors that, but I think those are reasonable statements. Risk of exposure is high, you likely will cross paths with someone who has it. Risk of infection if you take care is lower, but still moderate. Unless specific spots become major outbreak centers, I don't think you can point at any location as of right now and say "This spot is an unusually high risk and we can improve our odds substantially by avoiding it". Risk of dying is very low, but higher than would be normal for this trip. Risk of serious complications is quite important to consider.