Some people have been known to stash a bike at their office.
If you have a mountain bike you can pack it into a pretty small space by taking the wheels off.

If you put a wrench with it so you can remove the front forks and handle bars you can usually fit a bike into a large duffle bag.
A bag they use to pack wheel chairs for travel by plane or train should do nicely.

It usually takes 15 minutes or less to pack or reassemble one.
It helps to have enough cable to let you remove the handle bars without needing to unhook the cables.