nelliestar, sounds like things are going great!
My eldest was high sleep needs also and while he dropped to 1 nap at around 13-14mths, he did long nights, 6ish-7.30ish. So as long as he's happy I'd go with it.
Noticed you're from Nottingham-I'm in Derbyshire, so not far from you!
Our day went great, almost 2 hour nap at 12.45 (had to do WIWO to get him to sleep in the cot, as he generally sleeps in pucshchair but I decided this has to stop but thats a whole other thread!). Woke at 2.30ish, and very tired after dinner but went down without a peep.