In the past 6 months, I have been to Michigan (Metro Detroit and Ann Arbor), Portland Oregon, Naples Florida and I am about to head to Denver. My mother is heading to Costa Rica next week. I never really stopped traveling by car, although visiting my parents was tricky because they would not accept visitors until everyone had vaccines and boosters. I started flying again last year. In Naples, I met a lovely couple from Quebec who told me they needed to get an antigen test within 24 hours of return to Canada. They also told me that the regulations for travel had changed while they were in Florida and they were racing around to get tested. So make sure you have a plan for meeting Covid regulations and also a plan of what you might do should you become sick while out of town, etc. I carried one rapid test in my luggage since they were hard to obtain in my community, however they were easy to find in the places I visited.
FWIW, there were no problems with mask wearing on my flights. However, two flights were delayed, one for weather and one for unclear reasons. DD and my mother have also encountered multiple changes to their flight itineraries and more delays than typical when they travel. Airlines and airports, like most businesses are short staffed. Flights seem to get cancelled and delayed more often, and it seems things run slower, so plan on delays so you aren’t disappointed. There is a large billboard advertising for TSA agents on our local highway, etc.
Rental cars may also be an issue as they remain in short supply. Car rentals have been more expensive than my flights. The agencies have also been short staffed and lines long. Twice, the size of car I reserved was not available, and I had to take a smaller car. I found this frustrating for multiple tall adults and 80+ year olds with poor mobility.