the general advice is to increase the amount of yeast if you plan to freeze, as freezing kills some.
how to freeze? airtight. If necessary, to prevent sticking or deflation, freeze unwrapped for about 1 hour, when it is solid, wrap tightly.
i normally don’t freeze fully risen dough, as you would need to thaw to room temperature in any case and dough would rise a bit more during this thawing process.
don’t know if you can fry fully risen frozen doughnuts, frozen, try it, it may work and be so convenient!