Originally Posted by
rjw242
It's not a perfect correlation, but upgrade and MileSAAver availability often appear together. Using an award search you can see SAAver availability for an entire month, then use the normal flight search to confirm whether systemwide upgrades are available for those specific days.
Expertflyer is most accurate, but this is a cheaper way to find some dates if you're flexible.
I'm going to disagree with this. The strategy is workable but you would be leaving a lot of possible upgrade opportunities on the table. On a 3-class aircraft, U is rarely available without C availability; however, the converse is far from true. So you could be missing a bunch of dates where C might be available but U is not.