This will be a post on ways you can still enjoy festivities even in small groups or alone, (using Thanksgiving as an example for the most part). For larger groups, see Here.
While huge gatherings for the holidays are chaotic, they are fairly simple. The host house cooks a few of the bigger dishes (meats and oven sides that take the longest), and others bring in the rest. This is very similar to a potluck.
With a personal thanksgiving, what is most important is that you are having what you want! It’s a personal celebration; what you think and how you feel is the most important part.
For instance: I don’t really enjoy turkey. So instead of spending hours cooking a bird I won’t enjoy, I can skip that and substitute a different meat, maybe chicken and/or steak. And instead of several pounds of it taking hours, I can have it done in like 5-10 minutes.
My wife would enjoy a green bean casserole and some cauliflower mash with a side of keto bread and cheese. I enjoy mashed potatoes and gravy, bread, cranberries, and some chicken. I can trade out the potatoes for cauliflower mash to ease preparation, I just prefer the traditional starches. This means not only that some traditional foods can be cut from our food preparation, but we don’t have to prepare huge amounts. That being said, you can make huge amounts for few people and then subsist on leftovers.