I've made a very similar dish quite a few times, it's one of those things that I just whip up without a recipe. I will say I use a whole lot less butter, less cream cheese, and I mix the cheddar into the potatoes. Also I don't use garlic, I'll do salt and pepper,maybe a bit of green onion or Tabasco. ..maybe some Parmesan in there too, or sprinkled on top. Well, actually, I mash the potatoes then start adding a bit of cream cheese, sour cream, touch of milk if too thick, cheese, seasoning....I taste as I go along.
I see no reason why you can't include skins if you want. I've also made them ahead of time, just pop them into a 350 to 400 degree oven til hot, usually @ 30 min. I found that if I let it sit in the fridge, then bake it, I like to sprinkle on some cheese or dab small bits of butter on the top.

Glenda - my "do ahead" mashed potato recipe is very similar to yours, but doesn't use the garlic or cheese. It's along the lines of traditional mashed potatoes and goes well with gravy. I see no reason why you couldn't leave the skins on the potatoes in the recipe, but I think the electric mixer might not be kind to the skins. I don't know what would happen. I might mash them with an old-fashioned masher. You might want to have a "dress rehearsal" before taking them out in public LOL!!!

Anyway, I've used this recipe since the early 80's to make my life easier at Thanksgiving:

D0-AHEAD MASHED POTATOES
(12 servings)

9 large russet potatoes (approx. 6-6 1/2 lbs) - peeled & cut into large chunks
1 cup sour cream
6 oz. Philly cream cheese, room temperature
5 + 3 tablespoons unsalted butter (1 stick total) room temperature
1/2 cup milk
1 tablespoon onion salt
pepper to taste

Lightly butter a 9 x 14 oval baking dish. Boil potatoes until tender - drain. Use an electric mixer, mash potaotes in a large bowl with remaining ingredients using just 5 tablespoons of the butter. Transfer to buttered dish. (Can be prepared up to 2 days ahead at this point).

Preheat oven to 400 F. Slice remaining 3 tablespoons of butter, place on top of potatoes and bake until heated through and light brown, about 30 minutes, uncovered. (Note: if preparing ahead, let the glass casserole dish sit at room temperature for about 1/2 hour so it won't crack when you put it in the hot oven!)

Hope this helps you.

seagrass

Here is Rachel Ray's Smashed Cheesy Potatoes recipe. I saw her make these and she does not remove the skins.

Cheesy Smashed Potatoes
Recipe courtesy Rachael Ray
Recipe Summary
Difficulty: Easy
Prep Time: 5 minutes
Cook Time: 12 minutes
Yield: 4 servings
2 to 2 1/4 pounds baby Yukon gold potatoes
1/4 cup sour cream
2 cups shredded Cheddar
3 tablespoons chives, chopped or snipped
Salt and black pepper

Cut potatoes in half and place in a pot. Cover with water and bring to a boil. Work on other dishes while you are waiting for the water to boil.

When water boils, add the potatoes and some salt, 2 big pinches, and boil for 10 minutes or until tender. Drain and return potatoes to the hot pot. Smash potatoes with masher and combine with sour cream and cheese. When cheese melts into potatoes, add chives and salt and pepper and re-smash. Taste the potatoes and adjust seasonings.