Normally for a flight into the US - even a connecting flight - you would need to collect your bags at the first point of entry into the US (ie, Chicago), clear immigration/customs, re-check your bags, go through security, and then to your gate. However there are a few exceptions to this, and yours is one.
Passengers coming from most airports in Canada (including Winnipeg) actually pass through US immigration and customs at their departure airport - a process called "Preclearance".
Thus when you arrive in Chicago, you are treated as a domestic passenger as you've already cleared immigration/customs, and you are let out into the general airport air-side area.
Given that both of your flights are on Star Alliance airlines, and especially because they have been booked on the same ticket, your bags WILL be checked all the way through to your destination.
Thus on arrival in Chicago all you will need to do is make your way from your arrival gate to the departure gate. Air Canada uses Terminal 2, and Lufthansa uses Terminal 1, however these two terminals are connected airside. Depending on the exact gates used on the day, this would be no more than a ~10 minute walk.
So yes, 80 minutes will be plenty - with the usual proviso's that it presumes that your inbound flight is on time. Personally I always try and allow more in situations like this, not so much because it's overly risky, but simply because if you do miss the connecting flight the delay to get on another flight might be significant (although as it's on the same ticket the airlines WILL put you on a later flight free of charge)