I agree with both of you that Miss Bingley probably missed a step or two en route to that special license. ;-) But Miss Bingley isn't really in this chapter at all, except as the wrench being thrown into the Darcy's honeymoon plans. In fact, the only other people who appear in this chapter--apart from Lizzy and Darcy, I mean--are Mrs. Hale and the unfortunate rider whose horse threw a shoe.

I was puzzled by this too so I went back to the book to attempt to unbefuddle myself. ;-) I am now persuaded that the key words in this quote are, "a lady's imagination." Lizzy, like so many brides before and since, probably had imagined what her wedding night might be like. I very much doubt that the tale we have read here matches those imaginings at all. Instead of a warm, welcoming, romantic setting, she finds herself and her groom in a house without food, heat or light; the place looks uninviting and the housekeeper probably thinks that Lizzy and Darcy are housebreakers before she actually sees them.

The wedding night of the lady's imagination and the one that occured in reality, no doubt were very, very different. :-) That's what I think it means, anyway. :-)