Bridee i agree with every one else.
DDwill wake up the same time regardless of if she goes to bed at 6pm or 8 pm... i wouldnt keep him up as it could make him grumpier and then a worse night sleep.

I dropped night feeds at 5 months. i was hard but i refused to feed dd b4 5am - it took about a week but she then slept through every night since. also stopped dreamfeeds about 6months and she didnt wake up still so i figured she didnt need it and wasnt hungry so why wake a sleeping baby?