Originally Posted by
cornishsimon
I'd personally try and tack on a tier point run to the OPs upcoming JFK trip and that way get back to silver fairly soon into his/her new membership year.
cs
This is actually the most sensible because if the OP can get Silver quickly into her new membership year, she can also keep silver into the following year too. Broadly speaking it's difficult to get TPs for less than £3 each in Europe (and usually it costs a lot more), but not difficult to get them half that (or even below £1 each) on particular TP runs in the USA. She would still get lounge access for the Kennedy trip based on the timelag between membership year and card expiry date, but the TPs will definitely zero out on 8 December.
There is flexibility on BA's side to extend membership years by up to 2 weeks, but not only does this fall outwith that limit, it is probably best to back silver quickly in the following year.