Dipole antenna RF Layout
Does the antenna manufacturer really specify the ground stub as a simple mirror of the chip dimensions? Seems slightly odd. There is no reason why you can't use a trace which curves around, but it must not be flooded in your ground plane - this is intended to be a resonant ground, so the far end will be high voltage, zero current. You would obviously have to prototype several variants to get this to work well, but what you ask is possible in the space you have. I would start by re-routing the feed further south though, you need space similar to the keep-out around the chip antenna.