I usually freeze them after peeling, coring, slicing and treating with either FreshFresh or Lemon Juice and water. Drain and freeze in amounts needed. If you are going to be using them just for pies then it would help to put them in a pie plate to freeze the pop that out and bag.
But this year I made
Freezer Apple Pie Filling - OAMC, I put them right into a pie crust, top crust was excluded because I ran out of flour. But I baked one before freezing with a crumb topping instead. The only things I have to say about it is I think it needed more spices, I did use a mixture of nutmeg, cloves, allspice and ginger instead of just nutmeg. But I could have used more. And it made 5 pies instead of 4. I used disposable foil pans for these because I have only 1 regular glass pie pan, I think I might look into buying more regular pie pans as time goes by so I don't have to use disposable pans. I loved the taste even without the extra spices, I find it is going to be very convenient to have in the freezer.