Try googling "extend minnesota redemption period". You'll find lots of information about your rights and explanation of how the foreclosure process works. There are several references to extension of the redemption period by bankruptcy. If you don't already have a buyer in hand you are going to have a hard time even if you manage to somehow extend the redemption.

Lenny is correct in everything he said.

To my knowledge there is only 1 way to get this done (technically), and that is to ask a judge to extend it. I have heard of people trying but have never heard of it being granted. The best way I could suggest is to ask your mortgage company to allow you to close after the redemption ends (get this in writing), this is very seldom granted as well. You are mostly likely out of luck.