Go with the uninsulated wool, unless you're going to Saskatchewan for all day sits.
I have the uninsulated Day One ASAT wool bibs and they are more than enough for Michigan and we typically sit in Michigan vs moving around much. While you can wander on large public tracts in the UP and NLP, most hunters in Michigan walk less than a mile and then sit, due to fencelines and posted signs.
With that said, the uninsulated wool that Gary from Day One has on the ASAT wool is heavy. I can't imagine needing the insulated ones, unless going out in zero type stuff. As long as you buy a size up, you can put a ton of layers under the bibs. But, when it's around 45-50, you can still wear them if you go really light on layering.
One non-conventional suggestion for layering is the Simms fleece bibs. I used to own a fly shop and these are used when wading in rivers for Winter Steelhead. These are the bomb for cold weather layering. They are too much if much above freezing. Most hunters overlook these great layering bibs. They are dead quite...
http://www.simmsfishing.com/guide-fleece-bib.html I believe my old store still carries them too...
http://www.fishbaldwin.com/index.cfm