Okay, I admit it, I'm embarassed! For the party I'm doing on the 16th, they want mashed taters with horseradish/chives; I want to do as much preprep as possible, meaning I would like to make the potatoes in advance, and then reheat them on site. Tried it at home over the weekend, and they flopped! Made the mash, then piped them all pretty on a sheet pan, cooled in fridge. When I reheated them in the oven, I watched them turn into little puddles with squiggles! I've always made potatoes on site before, so they were served right when made, but there's just not enough time/help to do this. The only things I can figure are 1) too much cream/butter; 2) the cooked potatoes sat in the water a little too long, as I got a phone call and forgot about them - ? absorbed too much water? Thanks in advance!