SE Wisconsin - Any known sources for free sap buckets?

I normally get my buckets from Roth Sugar Bush in Cadott, but likely won’t be headed that way anytime soon.

Does anyone know of any specific sources for free buckets? Looking for used, food safe options like bulk frosting or fruit containers at least 3-4 gallons in size.

I’m going to check with some local supermarket bakeries, but thought I’d tap the group’s collective knowledge first. Anywhere between Madison and Milwaukee would be great.