I bet Lard Butt will keep extending it into June (maybe July!) if he continues to be able to act as Dictator of Illinois.
Maybe Fieldmarshaldj can answer this one, what is the party makeup of the Wisconsin Supreme Court? The main difference between them and the IL Supreme Court is that the Wisconsin SC elections are officially "non-partisan", but EVERYONE knows what party the judges are affiliated with anyway, and the donations they get follow suit (a "non-partisan" judge that votes RAT will get funded by Planned Parenthood, the Sierra Club, AFL-CIO, etc.)
I doubt the court has a clear "R" majority, otherwise the RATS would be dismissing the decision as "partisan partisan partisan" and run attacks ads about how "ultra conservative Republicans judges want Wisconsin citizens to die"
I don't think the SCOTUS at the national level would agree to hear any of this, as each state has their own standards for how draconian their lockdowns are, and thus a decision about one state's lockdown order would not be legal precedent for another state's lockdown order.
I think the issue is has legislation been passed that gives the governor emergency powers.
Lot's of states grant the governor broad powers once an emergency has been declared.
I believe the Wisconsin Supreme Court is like 5-2 Republican.