In reply to Robin Woodward:
We did the Sorapiss Circuit in July - really enjoyed it! We did the first two sections of VF starting early from the road, then stayed in the Bivacco Comici overnight, and finished off the following day. There were 6-9 bunks, all with 2 blankets on them, so just taking a sleeping bag would be fine. We were the only people in the hut (4 of us) and it was roasting hot. The other hut was similar, I think (we had lunch next to it earlier on the first day).
No idea how full they'd be in September, though the logbook in the Comici hut did mention a night a week prior to our stay when 13 people had turned up and some had had to bivvy outside!