you're talking about Bolzano, aren't you?

easiest would probably be driving (if you take rental car, you should drop it in Grenoble again which doesn't fit with with your flight leaving from Verona), train means change in Chambery, Milano and Verona and will take prob 10h. no easy flights come to my mind. you could try to get to Lyon or Geneva and then try to get a flight, but I am not sure if that will get you anywhere close ...