I am still without a solution, so far I have:
1. Opened a support case with Tesla. They recommended I shutdown the Tesla (which I did) and boot back. This did not resolve it. Now they want me to schedule a service with the service center. I'm holding off for now because this really feels like a software issue. Tesla support said they'd get back to me after researching this issue with other customers. They never did get back to me. I sent them an email this afternoon detailing the issue from the begining (no response yet).
2. Opened a case with TeslaFi to see if they've noted a similar issue with other cars in their fleet running the same code. (no response yet).
3. Posted a note to the TeslaFi user community to report the issue (no response yet).
4. Since this also broke the integration with the SmartRewards program, where one can get incentives for charging off-peak, I also opened up a case with FleetCarma. They acknowledged the issue, but have not yet pushed a fix. They said this has been a problem with Tesla's rapidly changing code base.
Note:
Some users have reported that changing their Tesla Password (invalidating API keys, and effectively shutting out access to 3rd party apps) has helped.
One user reported changing their TeslaFi polling settings helped them (
it did not for me).
In the mean time, I have not yet removed third party app integrations. I will towards the end of the week, barring other options.
Here is a chart (from Tezlab) showing my daily Phantom Drain (red selection) since the update. One can easily see the difference. During the winter, I can expect up to 100miles of phantom drain in a given month, and I'm now seeing over 100miles of phantom drain in a short number of days. Some days are worse than others, but it is not uncommon to have almost 30 miles of lost range per day (the worst day I had 46 miles of lost range).
Phantom Drain Chart Below: