For Mashed, one can make a fantastic batch using Red potatoes (leaving the skins on, mind you, for the full “dirty” effect).
Likewise, as an alternative, white sweet potatoes can be coaxed into mashed as well- but skip the cream/milk entirely, and only add a bit of butter and salt. Works best if you bake them instead of boiling them.
Whatever you do, do not mix varieties of potatoes for a batch of mashed. Ever.
For roasted, you can mix and match provided:
They are the same family (high starch/medium starch)
Sometimes, when feeling ambitious and wasting time, I’ll peel them, cut them small, and boil them. But just keep going and let it cook itself down. If the heat is low enough and you don’t scorch it, it will eventually thicken itself down to a very creamy super smooth potato paste which is DELECTABLE with butter and cream. And for a fancy variation, put masaman curry and coconut milk in. Masaman curry potatoes are wonderful.
I always do 2 or 3 packages. You don’t want to get to the day after, you have your sandwich all piled up with turkey, stuffing, gravy and then you realize DOH! no more cranberry. Don’t make that mistake, just make extra cranberry.
First thing that comes to mind is, what is the sound/noise level like? Lots of conversation and background noise? Especially if it’s not a younger person, maybe it’s hard for them to distinguish sounds and take part in conversation, and they give up trying and just sit back and watch? If that might be the case, perhaps somehow arrange for the environment (at least around them) to be quieter?
Also, have you tried asking them each directly, ahead of time, for suggestions on what might make the party better, from their perspective? You may or may not get info you can use, but it might be worth a try.
And @TobinL things are quiet, and board games are , ahem, on the table.
I had a quick phone call an hour ago, and I think a “goofy photograph tour” will be part of the fun. That, a few good board games, and a nice bonfire?
Ive learned over the years that the most important thing is to designate. My parents/step parents on the photos, my guy friends on the fire, their kids on the games, and the single people on the music?
No brining. No marinating. No dry turkey. And if I’m really careful, the pan barely even gets dirty!
One caveat: do not use these with a Butterball brand turkey. It will turn into tasteless turkey mush.
I second the recommendation for cheap wine. I usually just buy the pre-mixed mulling spices and add a cinnamon stick or two. Maybe an orange cut in half, and some sugar.
Also good to make: Hot Buttered Rum. Use hot cider instead of water and you’ll be under the table before you know it.