Sorry to hear about this. I hope your in-laws make it through without more harm.
the story about testing is SO frustrating. Where I live, we're having a fun spike, where contact tracing is shit, test positivity is the second highest in the state, case rates are 4th highest, but you can still get tested. There are delays in getting appointments and many of the typical testing locations, which sucks, and only the PCR tests are available with a 3-day lag in results, which also sucks, but people are not getting turned away due to a criteria.
My friend in Tallahassee is able to quickly test often and frequently. it's a 10-15 minute drop-in process, with both a rapid test and a PCR test. He gets results from the rapid test less than 30 minutes later via text message. He and his wife (who is a HCW at several hospitals) get tested frequently as a result of potential exposures or when they have any symptoms. It sounds like a pretty dialed system that unfortunately is not being used enough by the larger population. That family have 2 young kids, one in preschool and one in elementary school. They do not know WTF they are going to do about this school year.....