As a silver I've basically given up getting an upgrade, particularly to MCO, where I used to get one all the time. I know some will say they get them, but are they traveling on weekends?
Anyway, I am now booking my husband on the same PNR and not splitting. Chances are I won't get an upgrade and I can get E+ at 24 hours, which is my upgrade these days

As a gold you can get them when you select your seat.
Or, I'll take the TOD upgrade when I check in if offered at a decent price. That's why I set a timer at slightly before 24 hours so I'm ready to check in right away.