Do not concern youself with the card/membership expiry date. It is irrelevent.

The only thing you need to be concerned with is the 36 month activity rule. This basically says that your account will remain active provided you have activity on the account (any entry) within a 36 month period.

So providing the most recent entry of freeloader miles () is not more than 3 years old, you are fine. If it gets to the 3 year cutoff and you still havent used them, look for a way to credit miles from a hotel stay or similar. In fact you could just issue an award for a one way eurotrip and then immediately cancel it and get the miles back, it would cost you £25/$?? but it would suffice for the purposed of account 'activity'.

As for what to do with the miles, you could buy 5k more each and then have enough for a WT+ to Club upgrade transatlantic.