To be clear, that one is smoking. All the chimneys on the main building are smoking, other than the one near (4) on the map you posted; The kitchen ones (6) are now out. (As are all the ones on the outbuilding and the mess hall.)
The group worked their way counter-clockwise around the steading, sneaking past both the east and north courtyard gates. They came down the west wall until they arrived at the kitchen chimneys. Having been inside, they knew that there was likely to be obstacles at the bottom - pots and their hanging apparatuses, cooking grates, hooks. But at least the fires were out. First, they had to get up to the roof, and they needed to do so without making any noise. The spell would help, of course, but it mostly masked their footfalls and caused the terrain to cover their tracks. It would not prevent the sound of falling, or knocking a stone loose from the chimney.
Okay, let's push things along if we can. Jack and Valda can get up and down the chimney without rolls. Climb is dc12 and can be made with advantage if someone secures a rope to the top. I'll need two climb rolls (STR: Athletics) one for up, one for down. Failure going up will make enough noise (you can describe why) that someone might hear from the watchtower, the courtyard, or the kitchen (I will roll); failure going down will guarantee that someone in the kitchen will hear. If you get to the bottom safely, gimme a stealth roll (dc11). Failure will mean knocking a pot or something in the stove, and reveal to the occupants of the kitchen that someone is in their cook stove. Otherwise, you can safely silently push the grates aside to get out (and stay hidden in the hearth). As long as you're making successes, we can keep going, but you might want to pause and wait if there's any failures. No one will fall unless they roll below a 7 on any climbs. They'll just make it up/down while embarrassing themselves.
Jack surveyed the large chimney for obvious footholds and quickly scampered up. Once at the top, he pulled his trusty silk rope from his back and looped it around the chimney, finishing with a secure knot. He then quietly lowered it down for the others to ascend.
Nodding at Valda, he then slipped down the chimney and back into the cooking pot so to speak. Once at the bottom, he glanced at his surroundings before looking to clear a path for the others to descend.
While the others were working their way onto the roof, Quinn flew high overhead, keeping a silent eye on the courtyard. Jack slid silently down the chimney to have a look at what they would face there. He peered over a cooking-grate, careful to not disturb anything. Though the fires had been doused, the iron grate was still quite warm, and the sooty chimney was uncomfortably hot and stuffy after the cool night air.
Inside the kitchen, a gaintess lazily worked at the final clean-up after the recent battle by relevelling the dirt floor. She worked with a rake, clearing the area where a trestle-table had been, now gone. Quinn's locusts had destroyed everything there, and whatever had been left when the spell ended had either been burned with the bodies, or buried under the dirt.
In the southern part of the kitchen, a giant commanded a quartet of surviving orcs. Though the main feast was over, hill giants ate at nearly all hours of the day and night, and this group worked still to serve cold sausage, crusty bread, jerky, fruit, and drink, to whoever higher-caste giants remained hungry.
Tenibor drank two pints from the gourde. His first drink (which tasted strong, bitter, and not very pleasant) made him feel thick-headed, but not particularly strong. His second, on the other hand, made him feel mighty, and somewhat aggressive. He grabbed the rope and pulled himself up, hand-over hand, barely bothering to use his legs for anything but the barest of support. He arrived on the thatch roof and crouched to stay out of sight of the watchtower, which could be seen over the top of the main roof, but didn't have very good sight-lines in this direction.
Then, he pulled himself from the roof up onto the chimney, and hopped inside. He put his hands and feet on either side, and shimmied down to the grate, where Jack was waiting. It was a tight fit with the two of them inside. Thankfully, there were two chimneys.
@TerraDave give me a stealth roll with disadvantage (because of, IIRC your 11 down out of a dc of 12.) Who's next?