I've been in Alps before on my S1000rr, and I only complained on motorways, but I had chance to strech my legs every 130 miles while refuelling, so it was ok. On GS and especially on GSA you will have to make compulsory stops to save your bum from ache
I heard June as well, but I hope that they will start delivering at the end of May, otherwise I'll have to source two wheels somehow for trip to Picos...