Petit-Sault was making a great year round wit, Tante Blanche. I think though in their recent conversion from bottled 6-packs to tallboy cans as the standard packaging for their lineup, Tante Blanche became a summer seasonal. Hoping it returns this year.
Picaroons makes a....oh wait, you said decent, nevermind. Grimross has a seasonal wit, and I heard their scratch series hefe is possible again.