Well now you have said something different. If you hot water bath them to finish you will lose ~ 50% of the smoke and they are no longer "fresh" sausage for the grill. They will need to be put in the ice bath to stop the cooking process also. Then bloom and freeze.
If you want to just get some smoke in them I would smoke them 2-3 hours and pull them out. Put on trays and almost freeze then package for the freezer.
When you want to eat them, thaw and they will need to be cooked. You can boil, grill or fry in a few drops of oil. On the grill they will be dry almost for sure with a 70/30 deer to pork. You will have about a 8% fat content and good sausage will need 20-30% fat. I boil mine in 3/4 of a can of beer. I would use the whole can but I can't help myself when I open it ..... These come out pretty nice, plump and moist - like these last night. I smoked these fro 3 hours and froze them. Thaw and boil in beer then into the main dish ... Haluski. I think this is what you are wanting to accomplish ?? These are brats 60/40 deer and wild hog.
Correct me if I am wrong, which I often am, and according to the bride - usually!
100# of meat at 70/30 = 70# deer at 3% fat and 30# of pork at maybe 18% fat.
70*3 = 2.1 and 30*18 = 5.4 for a total of 7.5# of fat in 100# of meat. That is 7.5% ... pretty dry.
I would up the pork if it were mine. 40% is about my minimum with the deer for the mouth feel and taste and I have fat added to the deer to make it 85/15 or 80/20 to start with. Nothing worse than dry sausage plus it will stretch the deer a little too.
So I would have 60# of deer at 15% and 40# of pork at 18%.
60*15 = 9 and 40*18 = 7.2 for a total of 16.2% fat in 100#'s. That is 16% ... low by much better IMO.
Also add 1/2 cup or a bit more of powered milk to the mix to hold the moisture a little better. Put it on dry at the final mixing stage. Sometimes I also add a few dashes of liquid smoke per pound of meat as a backup.
Your opening argument was the best method except for the cold water bath ... not necessary. But I think you will have some dry sausage on the grill due to low fat content.
100# at a whack is way over my pay grade too ... whew, what a job that will be.