I recently took a long trip on my DL1000A with the panniers and top case on and they were filled with stuff. I put 4 more clicks on the rear shock preload over my usual setting without the luggage cases. Initially it was just a guess, but worked out perfect for my trip. Set up is a personal thing. If I were you, after loading up the bike I would try riding a short distance without changing the rear preload to get a sense of how the bike is handling the load. Then adding a few clicks at a time, see how it feels and keep adding clicks until the bike handles and rides much the same as it does without any load.
