Since the Air 2 is still performing well, I might suggest using it till the next version iPad pro comes out and upgrading then. Most of the 1st Gen issues should be resolved and you have maxed out the usefulness of the Air 2. If battery life is currently not sufficient the a battery replacement is $100 (US) and could bridge the gap. Also most of the Apps should have been upgraded for the new resolution by then.
I waited 3 Gen. of Apl Watch before finally getting one so I feel your pain.
I waited 3 Gen. of Apl Watch before finally getting one so I feel your pain.