Some of the schools recommended don’t really fit your requirements for academic or real boarding.
I would strike LWC, Bradfield, Hurtwood, Pangbourne, Bryanston, Shiplake, Woldingham off for not being academic enough.
Wellington empties at the weekend (as does Bradfield)
If you want all girls, there are lots of expats at CLC, but I know a couple who’ve pulled their girls out as they weren’t happy. St Swithun’s in Winchester? St Cat’s Bramley? Wycombe? Check numbers in on a Saturday night.
Co ed - Brighton College? Marlborough? Canford? Charterhouse? Winchester now takes girls in 6th form. I know lots of expat families at these schools.
re Peter Symonds. It’s a great state 6th form. Very much sink or swim though. There will likely be excellent teaching (in STEM and languages particularly), but large classes and very little planned activity for students at the weekend, as the few boarders that there are (about 80/4000) mostly go home at weekends. Your daughter would have to be very confident to go alone, knowing no one.
I’m not sure what the rules are about overseas fees for uni these days (must check!), so you might be setting yourself up for huge costs if she comes with you. One of mine did some schooling in the UAE. The schools are ‘fine’. It felt rather like paying independent school fees for a shiny brand new state school to me. Very high turn over of young staff.
I’m a serial expat, so used to having to react to the change of countries / schools / jobs. I’d either rent a place in Winchester, send her to Peter Symonds College, stay with her and go to the UAE in the holidays / half term, or go to one of the co Ed schools I’ve named above which have good numbers in at the weekend. I’d actually stay away from places too near the airports, as they tend to be the ones from which there’s an exodus into London at the weekend.
Sixth form is over in a flash. 22 months with plenty of holidays, which makes the renting and staying with her more feasible. You won’t want to be in AD end of May to beginning of October if you can help it! Depends if company requires you to accompany your spouse, or if they only pay school fees rather than additional accommodation costs should you choose to stay here for a bit. Bear in mind the tax limitations for visits to the UK as a non-resident too.
Sorry for the ramble! Lots to think about.