I don't know the actual answer and I don't know the show - but as no-one's come forward on this yet, I'm going to throw in some possibilities as to how they could do it, based on other shows' working practices.
They require one set they can use as exterior/interior - the 'answering the door/coming home' scenes. As you can see from the image below [from your link], this is very likely a location shot - even in the still there is far too much apparent depth in the background to be fake.
Houses in general are too small to film in comfortably, so unless they are really only going to be using it for a short time they tend to do the 'walk through the door' scene on location and the first cut is then to a built set in the studio, much larger than the actual house.
Whether or not the set has a 4th wall [other than for live audience shows] may depend on directorial/shooting style and/or budget.
Quite often one or more of the external walls is removable, so which 3 are in place depends on the shot.
If they don't have a 4th wall, then the establishing shot would by trope be 'follow them in on location so we can see the fireplace' [where our set wall doesn't exist]. Once the audience are comfortable there's a 4th wall, we never need to show them it again; if we do it will be in another wide from the door, so they never get chance to properly examine the difference in scale.
Then we come down to budget and time constraints.
If they need to 'damage' the set, or alter it considerably, they have a couple of choices.
They can film all the 'damaged' scenes right at the end of the shoot, so they have no time constraints on getting it back into shape for next year.
They build two identical sets, can 'damage' one and keep the other pristine. That way they can shoot to the actors' availability schedule rather than the production's.
The entire season is shot in 'blocks', each block handled by a different director. Each block has its own build/dismantle/move schedule for sets. One main recurring set can be decorated for the start of the block, then while they're away on location for a few days, re-configured for the second half.
Some shows have literally mobile sets, on wheels, that can be slotted together in different configurations depending on "where in the building" the scene is supposed to be.
There is nothing in the wide still of the set that would preclude it being the "real" set. I see no impediment to a 4th wall being replaced.
The carpet runner on the floor at the front could be covering anything, it's impossible to tell.
The coffee tables look a bit weird, as nominally that area would be full of crew not diners, but are easily removed.
Between them, the carpet and tables look like a bit of set dressing to keep the front of the shot looking interesting - or have reference to something in that scene; maybe the characters on the "fake" set sit there for a bit of dialog.
In short, it's impossible to tell from the scant evidence I have, but there's no reason it can't be the "real" set.
