How long would this keep in the freezer?

Hi Alice! The short answer is: I've kept homemade ice cream in my freezer for months and still enjoyed it. The long answer: Freezers' freeze-thaw cycles (basically, temperature fluctuations) slowly affect the consistency/iciness of homemade ice cream. Which is to say, homemade ice cream is theoretically better sooner rather than later. So, you could make it now, serve it on Thanksgiving, and it would be great. Or you could make it in a week or another week. Really, whatever's best with your schedule! (Either way, just make sure to let it sit out for a few minutes before serving, so it's easily scoopable.)