Northwest of London?
 

My husband is going on a sudden business trip, to the town of Bourne End in Buckinhamshire, are there any nearby beautiful/quaint/charming places that would make a couple of days visit worth it?

Oooh! Pinewood Studios is there.

I don't know about that area but don't you have get there via London?

Buckinghamshire's Web page.

There's a Roald Dahl museum there.