as in 2012 i’ve done a one-day trip to Ayutthaya. it was very much worth repeating and getting away from noisy Bangkok.
i’ve walked basically around the whole island. google image search for Ayutthaya flood gives some hints why so many of the temples are in different stages of decay. i guess that January is off-peak period – i saw just few buses of tourist-kids, otherwise – mostly open empty spaces.