You pose an interesting question. There are numerous assumptions one would need to or can make. But for the sake of argument, assuming all income is fixed in dollars and you do not have a adjustable mortgage, your payments would not change. You would continue making and receiving payments in dollars and your mortgage would not be affected. Your biggest worry should be the other commodities you need to buy or pay for like groceries, taxes, energy consumption, etc. The Weimar Republic serves as an excellent example of what happens to a country that prints money without any assets backing the money. For reference go tohttp://www.usdebtclock.org/
My mom's parents (she's from Germany) lived through this period and every time she wants to stuff her dollar savings in a savings account I remind her of the Weimar Republic and she drops that thought. It took wheelbarrows of money just to buy simple basic groceries.
Sadly the media and politicians "float" the "deficit" as the most immediate concern when it's the total US debt that strangling U.S.!