What kind of wood are you using and how are you stacking it? What was your water temp this morning and what did you have left for coals? The firebox on the 5000 isn't huge, but you're also keeping things pretty warm- I'd say that's about par for the course to burn a full load in 10 hours. I'm not far away from you and have essentially the same stove but the next size up, and burned about the same amount as you of 20ish percent MC oak. My firebox is 50% bigger than yours but I was only about half full. Then again my shop is 1600 sq ft and super insulated but only 52 degrees. House is 2800 with a spray foamed walkout basement and a somewhat drafty upper level with 2x6 walls and fiberglass, mid grade windows- only kept at 71. Mine has been fantastic in terms of consumption up until the last couple days, so it must be pretty darn cold out there. I'd say you did just fine