Hi, Beth and welcome to DC!
Just my opinion, but I don't think I'd make a potato soup in the crockpot. I think after 6-8 hours the potatoes would be mush, especially if your crockpot is one of the newer ones that cook at a higher temp. The recipe you posted sounds delish, and it only takes an hour or two to make it stovetop.
If you want to try it though, I agree with Dawg and don't add your dairy until the last few minutes. Same with the cheese - dairy products don't do well with long crockpot cooking.