My ds6 has always needed a lot of sleep too. At 5 it would have still been common for him to be in bed at 6.30 and asleep shortly afterwards. He also could do long afternoon sleeps then go back to bed at 6.30 up to the age of 3 or 4. But if your son is needing help to get to sleep now it is different. Maybe you could negotiate the homework issue and just work on keeping him awake until 5.30 then putting him to bed for the night. It is a shame he will not see his dad but it is not forever.