You are correct, I don't have an ashpan.
I do have a long interior insulated chimney...ICC double wall stovepipe, and ICC chimney. I get really long burn times when I try. I don't tend to load the stove very full, and I don't get really high stovetop temperatures. Just ran a load hotter than I usually do, and the stovetop got to slightly over 400.
Last year my son and I tried to get the stove top hot one day...really pushed the stove, and we got to about 500. My PH just sits comfortably at about 350 most of the time. It maintains that temperature from about half an hour after starting a new fire, until about 1-2 hours before the small coals only stage.
My home is 3 stories, 46 x 32, third floor under the roof, but a big floor with a 22 foot shed dormer --three large bedrooms and a bathroom on the third floor. Haven't had the electric heat on since I got the PH, unless I was away from the home for over two days, and it was Dec to Feb. Don't have to worry about the house freezing until at least Dec. (when I'm away). If I am going away, I load for a good fire, usually with ironwood rounds, close the air all the way, or just slightly crack it, and know that the stove will crank out meaningful heat for a full day. House is pretty tight, and pretty well insulated, but tons of 1970's era Pella windows, and brutal Northern exposure. PH handles it well.
And yes, Ironwood is amazing. Need to get a new battery for my scale, and after that am going to weigh my ironwood and figure out how much a cubic foot weighs, then how much a cord weighs. My ironwood is very dense. All my trees have tight rings...I am on limestone bedrock. Roots go down a few inchs, and out a long way. A lot of smallish stuff went over during the Noreaster and subsequent wind...once the snow is on the ground and the ticks are less active, I'll go cut the ironwoods that are down. Two big ones (for ironwood) about 12 inch diameter. Those will heat the house for a good while.
If I put a big Ironwood round in the stove and don't poke it at all, it burns for many, many hours.
When I get back from my son's wedding, I'm going to choose a cold day to load the PH full of Ironwood, shut it down for a long cat burn, and see how long it burns, at what temp, and what the house temps do....
It's fun to play with this stove.