I was going to say that even now i keep a stash in the car at all times as i find more than 1 cloth nappy and a wet bag takes up lots of space. If thats not an option you could nappy bag the bits and peices and back pack the nappy stuff or vice versa
Interesting to see what everyone else does as i'll be inthe same situation soon but i plan to still keep extras in the car and get a bigger backpack