I do have a solution to not running wires that is not necessarily a good one if you do not want to buy a new receiver, but Yamaha receivers have a setting to setup speaker in a sound bar like arrangement where the receiver will use digital processing to virtualize surround speakers. I do not know if Denon receivers have a similar feature, so definitely something to check before buying a new receiver. Of course, room design may limit how effective this type of setup will be and you might be happier running a 3.1.0 or 3.1.2 setup and forego surround speakers altogether.
Also, if you have small enough speakers, you can hang the surround and/or height speakers from something like 3M Command hooks and run the wires through the 3M Command hook things that are more barrel shaped close to the ceiling to make the wire less noticeable. You may want to buy speaker wire that blends in with the color of the walls. Also, adding decoration and/or lighting could make the wire running to the back of the room less objectionable.