I'm EXP with only a few hundred EQD over the past year.

What's the upgrade situation likely to be like on PHX-MIA and back? I haven't booked anything yet, but it's a long enough flight that if my chances aren't good I'll just pay for F.

I'm also very flexible with travel dates and times so I can book something that's more likely to be an easier upgrade, if there's a big difference between different flights.