We add a little pork to elk and moose for hamburger and some types of sausage. Anywhere from 10-30% depending on the sausage, 30% for hamburger so there's good fat in it for burgers or meatloaf.
If we've got something more rank (gamy) like a big old mule buck we'll go as high as 50%.
OP don't let the smoker stop you from making sausage, just make fresh sausage for bbq'ing, frying or baking (some olive oil on tinfoil, wrap the fresh sausage in it, bake for an hour-1.5 hrs at 350) We commonly do that in the winter and seperately wrapped some olive oil on tinfoil, potato, carrot, onion, zuchini or whatever you have in the oven for 1.5 hrs Sort of a lazy mans supper that's tasty. The potato's take 1.5 hrs, but if you slice them and put them on the bottom in the oil they get a nice crispy edge.