Is it possible to properly perform a deep plane face/neck lift and CO2 in 1 hour and 16 minutes?

Every Surgeon operates at their own pace, so it is impossible to judge another Surgeon's work based on this criteria. However, in my hands, a deep plane facelift, which includes both side of the face and neck is about 3 hours, and I am not a slow Surgeon. In my hands, there are too many components and details to accomplish in this procedure for 76 minutes.

Sorry to hear you aren't having a great result.
The short answer is no, a true deep plane face and necklift is not possible in 90 minutes. You'd be stretching it if there were two surgeons operating concurrently.
There are many surgeons these days that claim to do deep plane facelift. It's a sexy term, and commands a higher price than SMAS and mini-lifts. This is why it's so important to ask your surgeon what technique they are doing and ask them to explain it.
A true deep plane facelift involves releasing all eight facial ligaments, and the necklift should involve dissection deep to the platysma for multi-vector lifting and subplatysmal contouring. This type of work takes (on average) 3 to 5 hours, depending on the efficiency of your surgeon.
Many surgeons aren't doing close to this level of technical work. Those that do have patients whose results last decades. Hope this is helpful.