Directing Airflow

Needing solution to direct air from a floor vent (4”x15.5”) under a couch. The vent is about 8 inches from the window. We live in a rental and this is the only place we are able to put this couch for our 1 year lease (we plan to move out, so just need a temporary solution). This living room is so small, the couch must be closer against the window, as it feels like it’s sitting in the middle of the living room currently.

I’ve looked at floor vent deflectors on Amazon, and the ones for underneath couches are 10-13 inches wide, the hole in the floor is 14.5” and the actual register length is 15.5”, so those deflectors are too short. Amazon also has vent deflectors that have adjustable widths to cover 15.5” however, they are not made to go underneath a couch (too tall).

We have double pane windows that seem to seal just fine but maybe that is because of the actual vent working the way it’s supposed to. Need advice on protecting my couch and temperature regulation. And how to direct air to literally anywhere away from the couch. Thanks!