Hello!
I’m planning to fly Athens - Houston on Sunday June 2.
The seat map on United website shows 20 biz class seats available on 2nd leg of this flight, from FRA - IAH. But I can’t buy economy class on United and be waitlisted with PP for some reason.
So I thought I would buy it on Lufthansa website which does let me buy Econ class (or Prem Econ) and then submit the upgrade request form on United website and request upgrade to Polaris using 40 PP.

Does anyone have thoughts or advice to share with me on how likely the upgrade would clear on the FRA - IAH leg? I can’t tell if there is upgrade availability?
I have called both airlines but neither of them can answer this question of course.
I asked the LH forum but they suggested I come here.
Thank you! 🙏 😀

It’s this flight- LH 7601 operated by United Airlines
BOEING 777-200/300

full itinerary:

Athens - Houston

Departs on Sunday, 2 June 2024

Total duration: 18h 40m

Total duration: 18 hours and 40 minutes
3h 5m
07:05Athens
Athens International E. Venizelos (ATH)
09:10Frankfurt
Frankfurt International (FRA)
Terminal 1
Flight duration 3 hours and 5 minutes
LH 1285 operated by Lufthansa

AIRBUS A3211 stop in Frankfurt International
4h 45m
Duration 4 hours and 45 minutes10h 50m

13:55Frankfurt
Frankfurt International (FRA)
Terminal 1
17:45Houston
George Bush Intercont (IAH)
Terminal E
Flight duration 10 hours and 50 minutes
LH 7601 operated by United Airlines
BOEING 777-200/300