Hey I am from MN as well! I can relate with the thick cover stuff. A peep sight can be very accurate, as you know at the range, but not as easy to pick things up as standard open sights. A scope is obviously more accurate, but is not better picking up targest, quickly, over a peep sight. If you practice acquiring targets with the peep, you can pick them up relatively fast, at least as fast as a scope.
If you are hunting real thick stuff and need very quick shots, I would suggest going back to the traditional open sights and just practice more, as they can still be very accurate, to 100 yards inspite of what you might have read. A 1.5x4.5 power scope would be a good power for a scope, if you go that route. Good luck!