You really have your contingencies in a row, especially with the pre-busting, D3 loading, and that steroid taper security blanket in your back pocket. IMPRESSIVE ARSENAL. I vigorously salute this plan.
I would just advise to get the shots form of Red Bull (or whatever energy drink), since those are way more convenient than the cans for travel. I've purchased such shots at the little airport stores by the gates before, but no guarantees there.
Seems the only insurmountable gap is the previously discussed denial of the zomig spray you've suffered. I'd say f**k the ergotamine, but you know that's not just because it has been found ineffective by others, but also because I'm biased from my personal experience.
I suppose others may opine on whether it's still of any use pursuing the O2 for after you land.
My prediction is you'll have a great, CH uneventful vacay, and will be raring to go on more and more of these afterwards.