Back again!
Yesterday we had 4 X 45 min naps, with last nap ending at 5.30, went to bed at 6.45, and slept through until we woke for dream feed and then he slept through until 4.15 for a feed and then I woke at 7 as we had nursery drop off to do.
Tonight, last nap ended at 5.30 again, but today we've has 3x 45 mins naps and one nap at lunchtime of 2 hours 30. I've really watched his sleepy signals and also kept one eye on the clock to try and understand what his a times may be. Again went to bed at 6.45 and tonight has woken at 7.45, where he resettled and 9.10 - we've decided just to do dreamfeed early rather than resettling and waking again in 45 mins.
It's just doesn't make sense, it seems as though the less sleep he has in the day the better he settles and sleeps at night!