I face a similar conundrum this year. My partner from Catalonia and I have been invited to her sister's wedding and there's no escaping it for me. I don't want to go as I told myself I wouldn't fly again (haven't flown in 3 years) but I'll be in the bad books with her and her family if I don't. She's gone ahead and booked flights for us. Travelling by ferry isn't an option due to the cost and time it'll take to get there and back (we're only going for a week). Of course air travel shouldn't be normalised, subsidised and supported by the government and they should instead subsidise and develop less polluting transport networks but they don't give a feck and pretend that it's all about our 'individual choices', when their chums in industry are let off the hook.
We all have our excuses for not doing the right thing but we live in a toxic soup where doing the right thing is made very difficult and often impossible if you're not privileged enough to escape doing the 'easy thing' instead. I planted 2000 trees last year and started growing my own vegetables this year and still feel guilt for the aspects of my life I haven't been able to 'green', even while almost everyone around me doesn't give it a second thought and our whole forever-growth, corporate system goes unquestioned by society in general.