My wife called me at work and said she needed me to pick up some things from the store on my way home - a gallon of milk, a gallon of orange juice, a gallon of apple juice, and a few other miscellaneous things. No problem.
Unfortunately, I had forgotten to take out my rain/cold gear bag, which completely fills up my left saddle bag. But with a little effort I was able to come up with a workable solution.
The orange juice and apple juice fit nicely in the empty right saddlebag, along with a couple big bags of grated cheese -- my son like's quesadillas for lunch. From the Pelican 1520 on the rear rack, I pulled out my shoe bag (with my street shoes for work) and my insulated lunch bag (empty except for the cold pack on the bottom) -- my electronics (phone, tablet, glasses, misc. junk) bag stayed.
This gave me enough room for the gallon of milk (on its side), a box of Balance Bars, a quart of half-and-half, and a 3 pound bag of salad. The shoe bag and lunch bag went under the elastic cord that criss-crosses on the top of the Pelican case.
Home is only a couple of miles from that store, and everything was safe and cold when I pulled into the driveway.