First......welcome to FT, xyz99!

You won't be able to get anyone to give you a solid %-age likelihood of chances for upgrade.

But I would wager that if you are absolutely locked into flying Sat -Sat, your chances will be lower than if you had some flexibility in dates.

But either way, 30k miles for a fairly inexpensive card is still worth it, so go for it.

Purchase your tickets, waitlist for upgrade and cross your fingers.