Get a folding bike and a carry bag cover. You can find good ones that ride really well (Bike Friday, Moulton, Ive, Pacific Reach Birdy) unlike some that have hinges in the main tube. Sell your current bike to pay for it. Then, when you move and get a landlord who is not an a-hole, you can decide whether to get a standard bike again.

The other option is to offer your landlord a special security deposit against any damage caused by the bike being transported up the stairs or placed in the apartment. You can get free standing floor stands so you don't have to screw anything to walls. Easiest thing is to set one behind a sofa to minimize space use; get folding pedals or removable ones (MKS makes some nice ones). Rotate your handlebars. done.