Hong Kong with 11 mo sleep-fighter. Night flight or day WWYD?

[CautiousOptimist]

We're about to book flights to Hong Kong in November, me DH and DS who will then be 11 months.
He's 6 months now and not a great sleeper. If we're at home with blackouts etc, he'll sleep 7 - 10.30ish before a feed, then sometimes till 1 sometimes earlier, then it goes downhill from there! If we're staying somewhere else it's worse. He's also not regular with his naps yet and finds it increasingly difficult to nap if we're out and about.
All very normal I know, and things might have improved by November.
If they haven't though, I'm worried about the 12 hour flight.
By day he's brilliant. A very happy chap if not tired and pretty easy to entertain.
So what should I do? Book a night flight, hope he sleeps and deal with it if he doesn't? Or book a day flight and reconcile myself to 12 hours entertaining a by then potentially pretty mobile and overtired DS?
He's my first and I've never done anything like this before so would be grateful for any advice from people who've been there.
Also would love any tips from anyone about Hong Kong with kids. I have't been before. We'll be there 2 weeks.
Thanks in advance!

I would do the day flight myself. The plane might make him sleep at some point in the journey.

Are you travelling economy? If so, it may be worth upgrading to premium economy if you can afford it.
I flew a lot with my DCs (on my own) and the oe rule that worked for me was to never let them out of their seats (except for going to the bathroom)
If you let them out then they just want to keep getting out.
I also used to drug mine (only a little ) but I think this is generally disapproved of now. My DC are old now. My Dr gave me a prescription for phenergan that used to stop them getting sick and helped them fall asleep.
You will find the flight to HK easier than the flight home due to the time differences - west to east is easier for DCs in my experience.

I always took all the kids food with me as I found it easier to be self sufficient. Although, I always had the option of using the kids meals.

I don't disapprove of Phenergan with little ones! you might find by Nov he is the other way around hyper during the day and a good sleeper. do you have to book the flight this far in advance OP or can you wait a bit to see how he gets on. he will be mobile and I think you are brave to do 12 hrs with one so little. good luck.

You will be flying at night at some point. Even though it is a 12 hour flight the time difference mean it will be night during part of the journey. We left Manchester at 10.30 on a Thursday morning and arrived in Hong Kong at breakfast time on a Saturday morning.

Thanks everyone for your responses. That's a good point about the time difference - so he'll need to sleep at some point either way. Will hope for improvement over the next few months, and in the meantime am finding lots of tips on here about ways to amuse him on the flight!

I'd book the night flight. It is a long time until November. Daytime at 11 months means he is possibly going to be walking which will make for a very, very long flight. Night could still be long but if his sleep improves then it could be a breeze.

Hope you are booking him his own seat? Bassinets are pretty tiny.