Hillsdale is also Toledo media market; Monroe isn't, although the southern portion of the county probably has access to TV stations. Granted, Hillsdale is significantly more red than Lenawee or Monroe so probably less of an effect there.
Either way, people would be surprised, but margins can actually swing in border counties based on TV Market Advertising... probably less so with a Presidential election than a Governors race or a primary, but it isn't insignificant either if you're trying to reach every single voter.
I didn't see it listed, but South Bend media market would be another one that's probably worth throwing a few dollars at even though it's in Indiana.... decent population base along the border in those counties as well