You may want to address that ice damming issue you look to have in those valleys of that roof sooner rather then later, A roof rake goes a long ways, Surprised they didn't go with a metal roof so that snow would unload.
Euro has been snow here for the last few cycles and the other guidance seems to be moving towards it, Typical of these SWFE's is totals stay consistent over a broad area where its stays as snow and in the range of 6-10".