At present all the models suggest that TS Nicole will make landfall north of Miami on Thursday, noon-ish. As ever though, these forecasts change over time, so 50 miles north/south is not out of the question. Meanwhile, it does look like the intensity will quickly diminish once it does make landfall (it may just, with a push, make it to a Cat 1 Hurricane just before landfall, but I doubt it). Almost certain that by the end of the week it will be gone.
I suspect that BA will provide some flexibility (although I have known BA to keep flying when local airlines cancel - not that it's unsafe, just better pilots!).