too early to answer your questions about Donahue.
ask again in late March or April.
chances are there will be at least some snow that time of year, even in a low snow year. you should be able to follow tracks and cairns.
but whether you'll need crampons/ice axe ... too early to tell.
Last summer, 4th week of June, I went over Kearsarge, Glen, Pinchot, Mather, Muir, and Silver passes. All except Muir were mostly snow free.
But 2013 was an exceptionally dry year.