Grayling resident here-
Opening week is totally weather dependent. If it doesn't get cold early, the woodies are still here. If it does...the local mallards are dock ducks. To the point that my wife had me a t-shirt made up that says "I shoot park ducks". Get on Google maps and mi-hunt, find a beaver pond and have fun.
I continue to hunt up here past opening week because I enjoy being outside and live here. That said I made multiple trips down to the Wetland Wonders last year because the odds are much better down there by the 2nd week of the mid season then they are here. In Grayling specifically..there's nothing to really hold the birds here.
Let me know if you have any specific questions about areas up here. My opening morning spot has already been locked in. Right now I'm scouting hard trying to find shootable Geese for the early season.
Bump