OK, OK - I know full well that one should book flights based on where one wants to go and not simply what is available for redemption. I also know that the US & Canada (in general) have good redemption availability whereas South Africa, South America and Australia do not.

For reasons on which I am not going to expand, it may be beneficial to make a short-notice redemption in F or J. On what routes out of London, in your experiences, might this be most likely to work?

I have about 200k miles and a 2-4-1, though the latter expires at the end of this year.

My apologies for the slightly disjointed nature of the request and my thanks for your responses.