My two cents. He's just fasting, they do that.
He will eat when ready.
Offer every two weeks as suggested until he takes food again.
Personally, I would not offer live if he's been eating F/T. He might take that sooner, but then might not easily go back to F/T.
My female has fasted every winter for the past 3 years (she's 5). She loses 6-9% of her body weight and then starts eating again, when she is ready. It usually is about 5 months.
I exclusively feed F/T and she always goes back to it and eats, just on her schedule.