They really need to just swap the Vuelta and Giro around.
This is nothing new for northern Italy in May – hell, Livigno is hosting the Winter Olympics in a couple of years time!
On the other hand, Spain at this time of year is nice, not too insanely hot like it often is in August when the Vuelta is held.
Vuelta now, then Tour, the finish with the Giro when the northern Italian mountains are not under 3m of snow.
Also, this wasn’t exactly unforeseeable so the current situation right now is a farce. They had ample time for Plan B and maybe Plans C & D as well but no-one seems to have considered that.