Don't do what we did over Xmas & New Year...
LHR-YYZ on BA J (using Avios and an Amex voucher)
YYZ-HAV on AC - possibly the most expensive 3.5 hour flight I have ever had in Y. And the connection time on the way back was much longer than ideal.
If earning tier points is a priority, maybe fly via MEX?
Otherwise until IB restart the MAD-HAV service, it's tricky to find a decent OW route to HAV. This is an old thread but may have soemthing useful
http://www.flyertalk.com/forum/briti...-oneworld.html
Good luck