Since the Detroit metropolitan public health authorities are concerned about the high spread of covid right now, it would seem reasonable to state that you are following their guidelines and isolating right now with your own household bubble, and for safety reasons, you hope that they can do the same. Perhaps you can prepare the Thanksgivng dinner as planned, and deliver it in a nice basket to their home, so that they can enjoy a nice dinner from you and your husband, and that when things improve and the positivity rate goes down in Michigan, you can all get together then. That might be one approach.
If you do decide to have them over for dinner, you can wear a mask, even if they don''t. Just say you are following CDC and Michigan public health guidelines, given the transmission rate right now in your state.
I know this all is easier said than done. But I hope you can find a way to decrease the anxiety you are feeling right now.
Also, we have to remember that the studies that say that booster shot effectiveness starts to show up at day 7, this is the day they started to measure it. They may not have measured at day 5. It didn''t start to work on day 7, it was building up to day 7. So at day 5 you also have some protection.
I have also been careful about people coming in to our bubble, but we have had to have people come in to fix the furnace (they were here for about an hour, in and out, and I was down in the basement with them in close proximity, no masks at all) and this was before the booster shot during the month of October. We also had a neighbor help us with some drywall on the ceiling of our garage (had to take some down as we had a water leak from the bathtub above the garage), and we all worked together for almost two hours, with his kids in and out, and none of them wear masks and are very active in sports, etc. This was in late September, we had the garage door open, but were all in close proximity to get the job done. We were all okay, although I was very worried after the fact.