Im certainly no expert, but in general ground meat doesnt last as long as whole cuts. We usually make 20lb batches at a time and often give around 5lbs away to friends and family. My family of 4 goes through that amount in a couple of months. I also put about 1/4 of the batch into patties (without stuffing into casings) as we use the sausage meat in pasta sauces etc.
I would probably want to eat frozen sausage within 6 months. Its probably fine longer, but 6 months is what I have heard is recommended by food/health people.