Hi DD1 didn't go down to one sleep until about 18 months but DD2 did at 10 months I just gave DD1 a big morning tea before her sleep and then put her down at about 11am. She'd only ever sleep for hr and half at longest. Now at 2.5 she doesn't need a sleep but I still put her in her room for quiet play. TBH I wouldn't drop him down to one sleep until he's really unhappy with being in his room. If he's happy to play leave him be. I dropped the girls sleeps when it got to the point where sleep time was a battle. If you really do want to drop a sleep then just keep him up a little later in the morning. My DD2 has her only sleep at about 10.30am and has lunch when she wakes up any time from 12-1pm. I HTH! x