I have tremendous respect for Professor Hogg--I regularly consult his enormous compendium on the Canadian Constitution--but he is not the only constitutional expert available to us. Just recently a number of constitutional experts were brought forward on a very similar request relating to the upper house, for consideration, through a Senate committee, of Bill S-4.
As an example, Patrick Monahan from Osgoode Hall comes to mind. If Professor Hogg is unavailable, I suggest that rather than trying to send a series of written questions to him, we instead approach Professor Monahan, who is also a very distinguished scholar. I think that would be a reasonable approach.