You can freeze or can them - either way would work fine for roasting later. Freezing is probably easier but canning them provides much longer storage. We usually can about 25-30 quarts of potatoes each year to use all sorts of ways - mashed, fried, roasted, shredded for hash browns, scalloped, potato salad, etc. A quick and easy way to add potatoes to just about any meal.

Another good way is dehydrating potato slices. That is very popular with many for long term storage and easy use.

NCHFP provides the detailed instructions for both pressure canning, dehydrating, and freezing.

Dave

PS: linked some previous discussions here on the subject too if you want to read through them

Here is a link that might be useful: potato discussions