The Never Never changes and Lea invested her power in matching up her garden to Harry’s apartment (I wonder what other stalkery behaviour she has been up to in the past which has yet to come to light). It wasn’t a natural congruence and she wouldn’t waste her power maintaining it with no Harry.
As a dedicated stalker once Harry’s apartment burnt down she would have fixated on his next abode, which was Demonreach, and out of her weight class, as is the Carpenters abode. Molly’s Apartment on the other hand oh yes she will have moved her garden there in a heartbeat, as Molly is her second favourite stalkee.
However you have to take Mab into account. Harry is now the Winter Knight, taking on Lea’s agreement with Harry and building on it so whilst the garden may be back she is likely to want more control of Harry (Mab is a control freak rather than a stalker). That is why I think it will be backing onto the Winter Knights apartments in Arctis Tor, same idea, different implementation, and a connection between her Dungeon and Demonreach, so Harry has to go past the large plaque saying “Lloyd Slate Memorial Torture Cell” to get to Demonreach, because well, Mab. Mab likes keeping Harry in his place, which is in fact actually her place. Mab would have to invest power to make make the connections but Winter Knight abode to Winter Knight Abode and Supernatural Dungeon to Supernatural Dungeon, probably wouldn’t take much and would stick fairly well once done.
Indeed the Mab Dungeon to Demonreach leg may already have been in place, it may have been part of the Gatekeepers route in the first place, very few would dare use it, but the Gatekeeper would have been cleared to do so. He could have come to Arctis Tor from the Outer Gates and to Demonreach that way.