I was looking in the archives to see if there was anything said on this topic before and found a thread discussing where Lady Catherine would have stayed on her trip from Rosings to Longbourn. Reading these post made me aware of the fact that Lady Catherine had recieved the alarming report two days ago. I missed that when I was thinking of my scenario. Now I believe she had a good(?)nights sleep in her own bed. Made a leisury trip during the next day. Found a nice place to stay, not so far from Longbourn as London. Slept well(?), had her breakfast and arrived at Longbourn during the Bennets breakfast.