What am I supposed to do with ATG once I get there?
This is an important issue!
I either buy bikes with plenty of storage already or rig up something once I get it (by adding storage, racks, whatever).
Cable locks can help, too, if your storage is full of other items (like when out shopping/running errands, or on a trip).
Sometimes I'll carry a light duffel along and stuff whatever I can't stow on the bike in there and lug it into wherever I'm going ... it's a pretty easy way to keep it all together and out of the way.
If you actually USE your bike for everyday transportation, on-board stowage room is essential, IMHO.