Oooh, I needed something like this. I’ve plateaued in this game, with no real idea of how to proceed, and I dislike resorting to full walkthroughs.
I got to room 46 today. Spoilers for those who haven’t.
I’m a little dissappointed in how little it seems to matter. I haven’t done the run after yet, so I don’t know if there’s major (or even minor) changes, and I have a fair number of puzzles left undone so I’ll probably keep playing, but… was that it?
Major spoiler with regard to Room 46 (I would recommend reading it, though, as I don’t see any way you’d reasonably figure it out on your own)
The first time you reach Room 46, it ends your day and the credits roll. All that seems to do is unlock a fun new floorplan you can draft. But the SECOND time, you can go in and look around. It has some interesting things, but no major game changers.
I’m just a bit into the post-46 stage, but I don’t think there’s ever a point where the game radically changes; it’s always about starting the next day from scratch and hoping to draft a combination of rooms and items that will allow you to solve something you haven’t solved yet.
The website I linked a couple posts above lists 168 discrete things you can find/solve/achieve in the game, and when I found Room 46 I was at 40something, so there’s still a LOT to do.
Also, you can sometimes do things that will have permanent effects; you can get an allowance, which gives you a certain amount of gold at the start of each day. There is one area you can find that will always give you two jewels to start with. There are room upgrades you can do, like the Nook having two keys instead of one, or a room always having a couple jewels. None of these are very significant in and of themselves, but they do add up. On a recent run I had over 120 gold pieces, but was never able to draft any shops that sell expensive stuff. 
Anyone managed to draft the Full House (45 rooms) yet? I got to 44 on a recent dream run:
(minor spoilers for the existence of some rooms)
I had the Blessing of the Gardener from the Shrine active, so I had 9 Courtyards in my draft pool. I also had the Courtyard, which cost a gem to draft, upgraded so that it always had 2 jewels. I also had drafted the Kennel, which automatically unlocks all doors in any rooms you dig in. Also, I got lucky in that all 9 of those Courtyards appear to be identical, which in this case meant that they all contained a locked trunk. And I had a shovel and sledge hammer.
So, I was constantly able to draft rooms that had three unlocked doors and contained significant amounts of goodies. By the time I ran out of room, I still had dozens of keys and jewels left over. (And PS: I still wasn’t able to draft in such a way that I could get into the Antechamber!)