Hello Lizz

If the fig you are growing is Ficus carica ‘Chicago Hardy’, ( or ‘Brown turkey’ which is listed as zone 7) it can be planted in USDA Hardiness zone 6, and with winter protection may survive. They will die to the ground and resprout in spring, with only the roots surviving because they are heavily mulched.

Here are details from Missouri Botanical Garden-

http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=364291

However, with our occasional “polar vortex” and other unusually cold weather events, it is safer to bring it indoors each winter. These cold events can kill the roots.

You are correct, my research-based references do not address figs and juglone. Several gardening sites have gardeners stating their figs grow fine near black walnut trees.

Figs( Ficus genus) are in the same Family( Moraceae) as Mulberries( Morus genus), and mulberries are tolerant of juglone, so there may be some factual basis to these observations.

A protected location near a brick wall may be your best chance for success. Here are some references on winter protection for figs. You can see that these are from states located south of Michigan.

http://ccenassau.org/resources/-fig-culture

https://njaes.rutgers.edu/FS1198/