Roasting potatoes in advance

I prep my veggies for roasting the night before (or several hours) with herbs, salt and pepper and olive oil. I let them marinate in that. When I go to roast, I dump the whole bagful onto a half sheet pan. If you leave the potatoes unpeeled, I think they'll hold better. I've never noticed a problem with them.

Reheating thoroughly helps somewhat, but there's only so much you can do. The texture will never be the same.

Blame it on the chemistry of starches. In simple terms, when a starch cooks a network of linked starch molecules unlinks, and some of the molecules bind with water. When the cooked starch cools, many of the once-unlinked starch molecules re-link (a process called retrogradation). That's what makes cold cooked potatoes mealy and cold cooked rice hard and day-old bread seem dry.

Reheating reverses retrogradation partially, but only partially. Which is why reheated potatoes and risotto and stale bread will never quite have the same texture as freshly made.

Here's how I roast and reheat potatoes - they keep well in the refrigerator if well wrapped.
Use unpeeled Yukon Gold or another medium-starch potato. Russets will not really work.
Cut into approximately 1.5" pieces
Roast with olive oil, salt, pepper, and any herbs you like (rosemary and thyme are good)
Let cool completely, then wrap/cover well and refrigerate.
To reheat, I put them in a medium-hot skillet till they're crisped up again and heated all the way through. They probably won't need any additional oil - you'll see it on the surface as they get hot.

Hope that helps!