like i said - you don't have to decide now.
pop back in a year and let us know what you decided and how it went. none of us (not even you) have got a crystal ball.
fwiw, my youngest has cerebral palsy, so every time we move to follow dh, i have to completely uproot her from successful care and therapy packages and start again with new waiting lists etc - as well as replacing brilliant schools/ nurseries for three kids. it's no biggie, really. i don't feel like a mug, and resent the implication that i should, because i have chosen to keep my family (largely) under one roof.
and it does make me laugh that you have decided that you will be miserable in london.
fwiw, with both dh and i, every time we have looked at a place and decided it wouldn't suit us and would be awful/ make us miserable etc, it has always turned out to be one of the best places we have lived. i am totally not a city girl (was brought up rural) and wouldn't ever have considered city life. yet we have lived in london and even glasgow
and survived to tell the tale.
no-one is picking holes in your relationship - but they are questioning whether the 'la la la hands over your ears' thing is a good response to 'can a marriage work if the husband works away?' which was your original question.
why ask at all, if your response was going to be 'well, clearly i know mine will.'?
but hey ho. good topic for an aibu.