I have not travelled overseas since this issue arose, but spoke to friends and family who were travelling overseas, asking them to check-in with the SA lounges they use that they know to require physical cards, including contract lounges, about US/CO FFers getting in without a valid card post-Jan. 31st, or with a letter extending status, or an old card with a sticker on it extending the date.

So far, the responses they've gotten back have been along the lines of: 'We have heard nothing about this from UA; but even if we do, we have rules we follow here, and even if UA sends us a letter, we won't be admitting anyone without a regular valid card.' One of agents apparently laughed at the mention of a sticker saying: "Anyone could put a sticker on their card".

I will very likely be traveling internationally myself the second week of February, so I'll know, and be able to report back, first-hand soon. But it doesn't sound good.