Why not just move them in chunks and let it do it's thing overnight? Once it's in iTunes, use iTunes Match to basically transfer it all "to the cloud". Once it'

Why not just move them in chunks and let it do it's thing overnight? Once it's in iTunes, use iTunes Match to basically transfer it all "to the cloud". Once it's there, activate Match on your iOS device and you should have all your music available and ready to download on demand.