Watertones nice to see a fellow upper midwesterner even if you are from Minnesota . I don't know how close you live to Lake Superior. But if you've haven't had much exposure to it you may want to consider a 20 degree and skip the 30 with a liner the extra weight and volume isn't really worth it. The only months you might be warm would be July and August. I just leave my bag unzipped and use it like a quilt during the warmer nights. The SHT sits close enough to the lake that you get a pretty steady on shore winds from daytime heating which will match the lake's surface temp which is generally below 50 degrees add to that a fog or fine mist that often follows the winds off the lake and a little warmer bag is nice to counter the damp air. Its based on my experiances from backpacking along the upper Great lakes and working at a golf course a few miles away from Lake Michigan.