I'm heartened in a way that I'm not the only one struggling with this. Tried to book flights for the family Lon (any) to NY (any). Nothing sensible in J so thought I'd try WT+. Nothing there so I tried MFUs WT+ -> J and even W->WT+. Still nothing, even trying the LCY approach. Well maybe one way, but nothing sensible for out and return. I could buy WT+ tickets in the sale which were reasonable one way and silly back (or vice versa).

Ended up burning some old Virgin miles - they had reasonable availability. I haven't had status with Virgin for at least 5 years and they still did better for me than BA. Shame.