Could my A/C issue be anything but the compressor?

If cold air comes out of ANY of the vents the problem is NOT the compressor. The problem likely lies with the air blend door and what controls it.

Does your answer change if in the two weeks since this started, the vents previously working are now cool, but not cold (it may be worth mentioning that since the good vent has stopped being cold and just cool, we have been experiencing 100 degree days).

The A/C compressor works to make the system cold. The air coming out of the vents is affected by the blend door and other parts of the air distribution system. If the air is cold anywhere the compressor is working. If you have decided it is the compressor, then replace it. Or a better suggestion is to take your vehicle to a reputable shop that has experience in HVAC vehicle repair.

Thank you so much. I am going to the mechanic that has been fixing my Saabs for 17 years (previously a Saab dealership). I was asking because when the car was under warranty, they replaced the compressor and it was about a $1,200 repair (if I remember correctly), so I am trying to brace myself for the cost. I do appreciate our feedback.

I hope the compressor is good and all that you need is some less expensive work done to get it operating properly. Best of luck with it.