We had a very similar pattern last time we got back, with the playing in the middle of the night for hours.
We kept lights off at night, and let him come to bed with me and play firetrucks etc quietly (I was there, eyes closed and dozing). He would scream if we tried to settle him in the cot, or made him lie down, but would play in our bed. Admittedly, ours was 2 yrs old, so easier to explain he could play but had to stay sitting on the bed.
Keeping the lights off or low, and minimal stimulation, no food in the middle of the night (but water was OK), reinforced to his body that it was still night time.
Took us a good 6-7 days to get back to normal. I remember your pain, as I was 6 months pregnant and v tired.