I also get about 90% of my heat with wood. Because I live in a 1920 built house the stove can't qute keep up when night time temp falls to 15 F, so I have the gas come on an hour before we wake up. Just had Mass Save air seal my attic and basement and add 4 more inches of cellulose on top of my R-50 something batts. Hopefully we will see a difference.
Been burning for 10 years. Using a woodstock fireview cat stove and go through 3.5 - 4 cords burning mid October to early April. Wood falls from the sky around here and its all free. Too much to get from neighbors, colleagues, and occasionally my own yard.