Miele Man makes a good point about quickly pitching the tent to keep things as dry as possible. Particularly an issue with a double wall tent if the inner tent is largely mesh. Packing so it comes out logically is a good idea, so is practice. The day, or rather night, will come when you must pitch it in the dark. At that time preparation and practice will be worth their weight in titanium.
An inflatable mattress has the advantage that it elevates one above any water that has gotten in.
Good luck