temporarily planting fruit trees

[seneca196]

I've got a few apples trees on m26 rootstock that have been in 100litre pots for the past couple of years and need to temporarily plant them somewhere as they've outgrown their pots. I was thinking of putting them in the ground for 2 years, whilst I move, to allow them to recover from being pot-bound and then eventually move them when I return. I figure they won't need watering or looking after whilst I'm away, as they will be left to get on with life in the ground, as most trees do. When I return I would like to lift them and move them to my new house/flat which hopefully will have a garden in which to plant them. If not, then I may get some huge 300litre pots and try to repot them. Any thought or ideas on attempting to do this?
Not sure how wide the roots are likely to spread in 2 years, or if I should try and line the planting holes with something, to make them easier to dig out.