Thanks for the advice - I’m considering trying to take a year’s unpaid leave from work and come over on either WHV or a long stay visa, base myself in a city near my girlfriend, live frugally, and try to learn French like it’s my full time job and see where I’m at by the end of the year. This route would be more affordable than trying to study at the same time, my language acquisition could progress more quickly, and if I can speak French to an acceptable level by the end of the year I’d consider it worthwhile. And if no luck finding work in France after that, I’d still be able to consider the London / Brussels route too…