Consider just going regardless of the wind but keep a few nearby smaller lakes ready to run to in the event Michigan is roiled up and unfishable. I’ve been there on days where even our charter captain will not go out in a 28 foot boat and that wind was 17 knots steady. But we have never had 3 days straight of that kind of wind.
If I were spitballing with the wind and your boat, considering you would be on the wind swept side for worst case scenario, I might fish in 12-13mph wind depending on the height and type of waves. Your boat would be fine in taller rollers but alternatively, a fresh wind chop making 3 footers can be miserable.
Then for size, try steady winds from the North making 6-10 foot rollers on the south end (which you would be fine in) but then the west winds just start kicking in and add to those rollers a 1 foot easterly chop on top. Ugh…tough sledding in a small boat in that situation.
But each of us have our own comfort levels for big water. Sounds like you have a good idea as to what you are getting into though. Good luck and report back!
And by the by, Port Washington is the town just north of Milwaukee that we traditionally fish out of.