2 questions: I have leftover brown bread, do you think making my own breadcrumbs would be an ok Panko-substitute? Second, how do these freeze?

Thank you so much! Yes I have already frozen the bread, which is why I'm asking :) Food52 is amazing!

Brown bread crumbs will work fine potato pancakes. Dry the bread scraps in a medium oven (325-350) spread out on baking sheet for around 15-20 minutes. Check periodically until the breadcrumbs are no longer spongy or soft, they should be firm. Remove from the oven cool. The easiest way is to process them in a food processor or blender until they resemble panko-sized pieces, just help things along, and break up any large pieces. Make sure they are completely cooled before storing in large freezer bags so there isn't any condensation forming in the bag. They will keep for several months frozen this way. Don't forget to label the bag with the date when you freeze them and as with all things taste before using.

Since the wheat bread will be darker than the white bread used for panko, they won't be golden brown, but rather a darker shade so you will need to watch them a little closer when they are cook since you won't get a visual golden brown when they are cooked. Instead tap lightly with you finger or back of the spatula you turned them with to make sure they are crunchy for texture. The taste will be slightly different but not so much that anyone would mind. In fact the darker color of the brown bread will stand a greater contrast when they are cut into.
If you have a lot of left over scraps consider turning some of them into seasoned croutons or cut them into squares for freezing so you can use them in bread puddings as well.