@hello1234, I have 'had' to be out of my safety zone for the past year+ due to a serious medical emergency/caregiving of a family member. I have practiced all of the CDC safety recommendations, even before we had the vaccine available and with fear and anxiety. Now that I have had all of my Covid19 vaccines, and my flu vaccine, I continue to keep the same safety precautions. I am fortunate that I have not caught Covid or anything else.
As a 12 year transplant recipient, I had already learned that I have to distance, avoid people who are sick, wash hands for my own health. I think that must have helped me to be cautious during holiday celebrations, even before the Covid19 era. And my close family/friends are super vigilant about watching out for my needs.

As for restaurants, I have a 'safe' restaurant where I am comfortable. It was where my son was a GM before his serious accident/spinal cord injury last fall. I was comfortable going there because he wrote the guidelines for re-opening after the Covid closure. We choose to go at the uncrowded times - aka 'old timers hours' - between 3;'00- 5:00. This works well for any restaurant that you are comfortable with, based on your previous experience.

Only you can decide, but I have thought of some things that I would consider:
Do you know where your family will be dining on Thanksgiving? Have you considered doing a trial visit there so you can see first hand if the environment is comfortable to you? Have you thought about calling and speaking to the manager (non mealtime hours) about your concerns? And about seating and spacing?

Are your family members following CDC guidelines? Are the members of your family vaccinated? Do they respect your food, drink, safety needs?