My father and his immediate predecessors are from southern Minnesota.In researching their past I have found references for them having been in Green Lake and Fond du Loc Counties, Wisconsin up until the 1870s. I have found a 'F Heidel' (I think a Fred.) buried in Brandon, WI. However, descendents of this Heidel do not suggest that of your predecessors.
I am finding more information online for Wisconsin than for Minnesota so you may be lucky.An interesting website for you may be www.wlhn.org