You can just cook them in the slow cooker. It takes 4 hours on high, then mash and keep warm on low or warm until serving. There are lots of recipes online, so google and find one that appeals to you.

I think it’s best to serve them within an hour of mashing. The mashed potatoes near the sides will start to get dry the longer they’re sitting. I’d let the potatoes cook a half hour longer on low if you need the extra time rather than having the already mashed potatoes sitting and waiting longer.

I'll make them day of, after the turkey goes in the oven. Thank you for the answers. Butter on top sounds good so they don't dry out.

Are you making them day before or day of?

If I do day of then into the slow cooker on low. You can do that for hours. Sometimes I put some pats of butter on top so they don't get crusty. Depending on what else is cooking I like the better covered with foil in an oven on the lowest setting.

If you do day before then you can reheat them in the oven with foil on the top. Those I make a little thinner since they tend to tighten up when reheated.

How far ahead do you want to make them? The main thing here is food safety. You don’t want to hold food in the “danger zone” for long period. There’s also a limit for holding hot.

You can keep them on warm, sure. I do that all the time. You might just need to add a little extra liquid before serving if they start to get dried out.

I always feel frazzled with the timing of getting the turkey dinner on the table all at the same time. Is it a good idea to make the mashed potatoes ahead of time and do you keep them on low or just warm? I'm looking forward to having the family over for Christmas dinner and wish I was more relaxed about hosting.