As the others have said, wytco0 unfortunately economy longhaul redemptions are a bit of a no go area in this board! We all know all too well how little value per Avios point you get when redeeming.

Options are a trip to Moscow (as the taxes there are Reward Flight Saver prices) - you could use a companion ticket for this if that would suit you?
[You can in fact fly to Moscow and Club World and First at virtually no tax cost which could be luxurious if you have the miles]

Across the pond, as the others have said Aer Lingus and Air Berlin mean cheaper tax, but no companion ticket use.