If you like it real smoky, and you used the cure like you said, you can take longer to smoke it, because you don't have to worry about the danger zone. If it's cured right, you can go to about 130˚ for a couple hours, then 150˚ for a couple, then 180˚/190˚ until it is 165˚ internal temp. Some would take it to a different internal, but most of my recipes call for 165˚.
I never use instacure. I use Tender Quick. My TQ is one ounce to 2 pounds of solid meat & only 1/2 ounce to 2 pounds of ground meat.
I know 1 ounce of Instacure is good for 25 pounds of solid meat, but I would guess that means one ounce of Instacure for 50 pounds of ground meat, however don't go by my guess. Wait until somebody who knows Instacure confirms that, or do a search of "Instacure & Ground meat/sausage".
I just looked, It appears to be one ounce of Instacure to 25 pounds of meat, whether it's solid meat or ground meat. I find this very odd, so I would still check with a regular Instacure user.