changing dates on a ticket upgraded with last year's E-voucher
I'm making plans to curtail my current trip to Asia: the uncertainties surrounding cancellations/quarantines is making me uneasy. I'm resolved to pay a change fee and any additional fare-class change, or buy a cheap ticket home from any carrier.
Clearly, though, it would be happier to pay a change fee on my existing ticket. Unfortunately this is an economy ticket upgraded with a a now-expired E+ voucher. My question is:
Can I swing the E+ upgrade into a change of date if the required booking class exists: or would the changed flight be in economy, regardless, and the voucher lost.
Sadly i am nowhere near a helpful TK sales office, and i can't face a call centre discussion.
So I open my question to the wisdom and experience of forum members!