I haven't got any advise really,only to say that when my two have their milk we always watch Fifi and The Flowertots,then Emily knows it's bedtime and now says night night.
Jessica watches Little Bear and goes to the toilet then asks to go to bed.
I'm quite happy with this as I read Jessica's book when Emily has gone to bed,but while she's watching Little Bear.
Don't know if this does anything to help,is it worth not having the tv on from about 4.30pm to see if he misses it.