By getting and maintaining the card, you get automatic Platinum Elite status.

Here is my question...when it rolls over in January, how long does it take to bump me back to Platinum Elite if I do not have the pre-requisite points/qualifying stays from the previous year?

This will be year 2 with this card.

One would think it would be automatic on Jan 1, however, this is in the fine print:

*- Platinum Elite status As a Priority Club credit cardmember, you qualify for an upgrade to Priority Club Rewards Platinum Elite status for as long as you remain a cardmember, and as long as your Priority Club Rewards membership account remains in good standing. Please allow 6 to 8 weeks for the upgrade to be applied to your Priority Club Rewards account.