Greetings taxloop, welcome to the British Airways forum on Flyertalk, it's great that you have finally taken the plunge to join in, everyone is welcome here so please feel free to actively participate in the future. And indeed come to one our Do's if you get the opportunity.

I am also irritated by departures at this hour and actively seek out day time flights, late ones really aren't good for the body. But sometimes there isn't much choice. Now in DXB isn't great for wonderful lounges, except perhaps for EK First, the BA one is OK but gets crowded, and the airport itself is an absolute zoo anyway. So personally I'd be pushing this the other direction: trying to minimise the bad bits.

So consider paying for a late check out. Some hotels in DXB will give you a very good rate for a 23 hrs checkout, and you may find it a small price to pay to ensure your vacation ends on a good note. Being able to rest and bathe before flying is a good thing to do. If not, maybe haggle something like 16 hrs and leave your bags there. Then fill up the evening with shopping, eating out and what not, with the meal perhaps later and lighter than you'd normally do. Personally I find a long evening swim before flying to be a really good idea.

Then get to the airport say 90 minutes before departure. As a First passenger that is fine for DXB since the BA ground staff are very good if everything stays to plan (if hopeless when the wheels come off).

Enjoy your experience (though of course keep checking availablity for the morning flight) and let us know how it goes.