High Mash Temp

Did an American Wheat wednesday and over estimated my strike water temp. I was intending on mashing at 155 for 45 min but took me longer than anticipated to cool down my strike water. My mash wound up staying about 165-169 for approx. 15 min before I panicked and put some cold water in. My pre-boil gravity was 1.028 and post boil was 1.042. It has stopped fermenting and is holding steady at 1.020. I know this is a bit high and through doing research on this forum have found out this beer might end up being sweet cause of the unfermentable sugars i created during mash. Is there anything I can do to fix this problem or am I going to be stuck with this one.

you're stuck with it, but don't despair until you taste it.

I'd say you're most likely stuck with it.

It MIGHT be possible to add some table sugar or even some extract directly to the fermentor to get some more alcohol in there to dry it out. That's not really a technique normally used with wheat beers (normally reserved for Belgians) so you might end up with some flavors not normally present in a wheat. Always fun to experiement though!

Or pitch some champagne yeast in very limited quantity. It might chew on some sugars that the beer yeast ignored.

I like the sugar idea, too. Ferment it warm and call it a ghetto saison.