Sounds good to me. I already do frozen roasties, yorkshires and veg - apart from new potatoes and carrots (I hate frozen carrots!) - so what is a bit more! My only concern would be the turkey breast not being big enough to feed 5 large appetites for dinner, sarnies and cold with chips and pickles on Boxing day! I could always buy two I suppose. No carcass to make soup though.
The starters probably wouldn't go down so well - I can't stand goat's cheese and I know my boys won't go near oysters or prawns. They also look heavy on the gluten. The deserts would be very popular - in fact, there are a couple of Iceland ones on our shopping list already!
The main difference will be that it is Dad who is going to Iceland as I don't do shopping!!