I'll be traveling United several times this year with a non-elite companion. I'm United Premier. I realize my chances of early upgrades are relatively low.
However, if we're on the same reservation, will United upgrade me only if there are two seats available (i.e. they won't separate us?). If that's the case, would I have a better chance of being upgraded ahead of time by separating our reservations into two confirmation numbers (as is required by CO on their flights)? I realize chances of two 1st class seats opening on these smaller planes is small, so just trying to maximize my chances.

Thanks!