If you are going to take the laptop my only option that I would consider is a Pelican laptop case. They are waterproof, dust proof, withstands temperature extremes, and crush proof. It could fall off your bike at 80 and survive no problems. I don't work for them in any way, but my company that I work for uses them all the time for some very sensitive government electronics equipment. I found one on ebay that isn't really that expensive either.
Ebay Item There is my 2 cents.
