If you don't clear as a silver, you definitely won't be clearing with an upgrade bid

Copa prefer to reward elites over making the extra $$$

Generally Silvers get upgraded at ~7.30am EST the day before you are flying - bids get processsed a few hours after this

As 2nd poster said, it's one of the harder routes. Some flights leave full, others have a couple of seats open. Luck of the draw

Flying to LAX monthly, should get you to Plat next year