It depends on the patients, and what strain is being grown. Most use around 1-2 oz a month, but there are also 4-8 oz a month patients. It is also possible for a caregiver to leave one of the patient slots open, and take on temporary patients. I haven't done that yet.
This is what I can get with the current Sour D plant I have:
16 sq feet / 600 watt / 90 days = 24 oz
I am pretty sure I could get it up to 2 lbs with more light and CO2.
But it gets tricky, because you are only allowed to have so much finished product at a time. So when it is done drying and curing, you have to unload half of it.
It also helps if you run multiple flower rooms and a veg room so you can do one harvest a month.
But 32 - 50 sq ft of growing space should be able to supply 5 patients. But that is raw growing space, and doesn't include a working area.
1000w will cover about 25 sq ft
600w will cover about 16 sq ft