Welcome to Flyertalk moscowa, welcome to the BA forum, and thank you for joining up with us here. I hope you will stick around since there's usually quite a lot of good information that you can pick up here which will make your life easier.

Firstly, I wouldn't bother checking LHR, the Orlando flights go from LGW.

Secondly getting CW redemptions to that part of the world during Christmas / school holidays is going to be tough. Availability is generally first available at T-355 days at 01:00 hrs London time, and then every day, at the same time, there may be other seats released. The next big wadge of seats to be released in the final days before departure, which probably is unhelpful, but something may crop up before.

Other things you can consider is booking a NY (PHL, WAS etc) service to begin with and watching the Florida flights carefully to see if a better option comes up. There will be a change fee, but it may be the easiest idea. The other option is to look at Aer Lingus availability via DUB (for which you need to call) or Air Berlin via TXL / DUS, which are both a great deal cheaper in terms of carrier surcharges. However generally both airlines only release 2 seats for redemptions at a time. Patience is the best thing here.