Out of the two, Domane - hands down.
What do you mean by "packed gravel," though? If you, in MI, have similar gravel to the limestone that we have in MN, even the Domane might be overkill. For dedicated paths, like rails to trails, even 28s are hunky dory and most modern disc bikes will accommodate (hell, every new Cervelo has clearance for 34mm tires, now). If you're talking about B roads, where the gravel can be more chunky and loose, and you expect/want to traverse at speed, yeah, go with something that'll get you in to the 38mm+ range.