All joking aside, they probably really are adapting to the cold, growing larger and faster than ever before. Natural selection would favor larger specimens in Florida more so than in continental Southeast Asia.
1) larger mass would be more likely to withstand Everglade cold snaps that are nonexistent in Burma. Reptiles don't generate their own body heat but a 100 pound Burm loses heat less rapidly vs a 10 pounder.
2) the significant decline in the population of small and medium prey leaves primarily only larger prey, e.g. deer, which fall prey most easily to the largest Burms. Significant declines in populations of raccoons, possums, bobcats, etc, have already been noted.
They're beautiful snakes really, just a shame they've become invasive.