I wonder what is the history of the cottage? It was present in 1897, but I don't know if it was also supposed to be there in 1795 and 1840? But what or whom was it originally built for? At least by 1897 it had lost whatever original purpose it served--certainly the caretaker didn't live there or anything of the sort.
I'm sure those more knowledgeable than I will correct me, but I'm pretty sure the cottage is there in 1795 and positive that it's in 1840. In 1897, Quentin certainly found it convenient.
As for getting Laura's things from the hotel to the cottage, if Matthew were still alive, Elizabeth would have him drive to the hotel to get them. But if Matthew were still alive, of course, Roger would have to put up with Laura staying in the Great House itself.
Once again, David appeals to the hated Miss Winters to make an excuse so he doesn't have to go downstairs to see his mother. Once he's alone he finally has a good cry. Later, when Elizabeth has talked him into putting on his pajamas, he tells her that only babies cry.