I'm heading up to Manatoulin on The 11th or 12th. I hear there is heavy construction on 6 south of Tobermory, so plan extra time. You don't want to miss a ferry.
In my experience, the construction crews are pros--they organize traffic flow and don't fool around. Ten minutes would be considered a long delay, if they're working. I was up there mid-June and the roads were in good condition.
Heading up again soon. The Chi-Cheemaun is on summer schedule (11:10 am crossing is popular), so you don't need to leave at 3 am to catch it. Get there slightly early and grab breakfast at Craigie's, in Tobermory harbour.