Leftover mash/fish cakes

[Cat98]

I have leftover mash in the fridge from Wednesday. It was mashed with a little butter and milk.
First q is - will it be ok to use for fish cakes and freeze?
Second q is - if yes, should I make the fish cakes now, freeze, and fry up when required, or freeze the mash as is, then defrost and use to make the fish cakes when we want them?
Thanks!

It'll be fine. Make the fishcakes and open-freeze them, then stack and pack them into a box for longer term storage. Cook in the oven from frozen

Thank you :)