in my opinion you have a very good system with the amount or wood you have burnt. i live in ontario canada but i believe our temps are about the same on average (i may get more winter winds of the lake?) i burn from october to april or may and burn (dependingn on the year) 10 to 12 cords (4x4x8) this year being a ten cord year
i have a bit of a leaky 2 story century old farm house (reinsulated where ever i have been able too) domestic hot water and keep my 30 x 40 shed above freezing for my dog to sleep in
i am thinking i can get dow to 8 cords with a little more work on the insulation and windows but that wont be until i can save teh money to do the job...cutting wood seems easier