The risk of Covid starts with the level of infection in your community. If high or rising,of course, you have to be more careful. If low or dropping, you can be less worried. The whole adventure revolves around your personal tolerance for risk.
If you are healthy, young and fully immunized, especially with a booster, you can take more risk. If you have actually had test-positive Covid, that counts as one injection.
Remember that your immunity begins to wane after 3 to 6 months.
If you have an immune deficiency, such as age more than 60, obesity, or a variety of immune associated illnesses, you should be more careful.
If you have decided to go to one or more holiday venues, you might consider reducing your exposure for a week before, or possibly take a rapid test the day before you go, as a courtesy to the other guests. At the party, you can choose to be as close to a window, or fan, as possible, or prefer those groups who are outside. Wearing a mask might also be helpful, and at least will tell the other guess that you are worried.
The catch 22 is that if you are really worried you might consider not attending the gathering. Distancing to more than six or 9 feet is still a good idea, but makes you seem like a Grinch, and is difficult at a party. Do remember that the greater the density of people the greater your risk. If you are a host, especially in an area where Covid is rampant, your guests should be vaccinated. You might consider asking your guests to get a rapid test the day before they come.
If you have children who are unvaccinated, you might ask them to wear a mask, and keep their distance from the guests. You could open the window a crack to improve the ventilation in the room, and hold as much as possible of the gathering outside your house. You could ask the guests to wear masks when they are not eating. The N-95, KN-95, and KF-94 masks are all excellent, and will protect the people who wear them to some degree, and be very protective against their spreading the Covid virus.
After the gathering, especially if good protocol has not been followed, you might be alert to the possibility of an infection within a week to 10 days following the party. If you develop symptoms, a prompt rapid test is advisable. If positive, you can check with your doctor about the possibility of IVIG, or other medications. If negative, and the symptoms persist, the test should be repeated, since they are not 100% reliable.
There are a couple of oral tablets that are on the verge of being approved. You might ask your doctor about fluvoxamine, an already approved medication.
Immunization is not a ironclad guarantee against getting the infection, or spreading it. Unfortunately, Covid is still lurking in the background, and gatherings for the holidays should be evaluated on a risk-reward basis.
For an interesting discussion of this topic, I would recommend the Sunday, November 21, 2021 edition of the New York Times, where three knowledgeable people discuss individual situations.