I do this on pretty much all of my short (1 or 2 night) trips, including last weekend. I've never had any problems. Come to think of it, I usually bring something similar on longer trips too, and just eat it by the first or second night. Maybe eat the sausage chunks the first night if it's going to be uber-hot and you're worried about it.
Idahoan instant potatoes + sharp cheddar chunks + summer sausage (or similar) = a Mighty Fine trail dinner. Obviously not the lightest, but for short trips who cares? I often roast the summer sausage on a stick over the campfire for added goodness.
This is just what works for me - so, ya know, please don't sue me if you hurl :)