Dinny has good questions.
I live in MN, and a little more info sure would help.
You could be on a power line or wheat field and have flat open for 1/2 a mile,,30-06,,308,,7-08
You could be in the thick, and not see further than 50 yards,,45-70,,30-30,, your 12ga slug barrel
What small game?,,.223 is legal here. (a little too small a projectile for MN deer and turf, IMO)
Find a smoothy barrel for your 12 and bring that with ya-- for Rabbit, Squirrel, Grouse, Pheasant
(if yer Grousing a short 20 is hard to beat)(look for barrels in the classifieds)
Off the top of my head, get a 308, then a smoothy barrel (12 or 20) with your slug gun and your set for what MN has to offer in terrain and cover.
Up here the 243 is considered a youth/ladies gun, the 270 has a following but poor in the thick brush. I'd put money on the 30-06 being the most used/popular round here in the MN Deer woods with 500,000 hitting the field opening weekend.