In your OP, you stated that your concern was keeping the pack left outside at night dry. But, here, you state:

Do you plan to leave your clothes and sleeping bag outside in the pack at night? Most of us use our sleeping bags for sleeping and clothes as a pillow.

And:

Everything but the food should be in a waterproof bag of its own and kept under cover at night. The food should be kept either in a distant bear canister or hung from a tree some distance from your shelter. Of course if you are writing from someplace where bears are not an issue then you simply need to secure your food from mice and such and then keep it under our shelter with you. Most of us here don't leave much of anything in our packs at night; most of what we carry is in use.