Cat, I'd just say stick to the RW prog for the target time, and don't start too soon. try for a late Autumn half if you can, following a prog for that, then if you get in pick up FLM training prog from there - Its usually 16 wk countdown, so with it being slightly later in April this time I think that may even allow for enjoying Christmas and New Year to the full!!
Billie, same goals, v similair times, I too dream of 1:49:59 half (!), but can't get rid of those last 2 mins!! Broke my arm recently so training is less than should be for Autumn half so only expecting to get round under 2 hrs this time!