CO Plat , my normal Saturday ewr-sfo flight (348) has been cancelled so I need to change to an alternate flight.

United flys ewr-sfo with a 757 at 6:07pm on Saturday.

If I choose this flight, it is possible to get a free upgrade or use co miles to upgrade?

United also has a premium service 757 from jfk at 5:25pm, can I waitlist for an upgrade using co miles on that flight?