10.5 plus 2017 MBP w/o Touch Bar is what I voted, because that is EXACTLY my set up. I have 256gb though on the 10.5, but only use about 70 and could off load or use iCloud better. I've just watched several videos, all which concluded most/many would be better served by the 2017 MBP w/o touch bar over the 2018 air. My MBP is incredible, and I've gotten used to the shallow travel keyboard.
I bought a 2018 IPP 12.9, but I returned it. Slightly too big in my lap, worried about bending if I tow it around, and didn't like their "smart" keyboard option. The 11 so far doesn't impress me as an upgrade to my 10.5. Prefer my "total package" 10.5 solution with Apple smart keyboard for when I am mobile or smart cover when I don't need keyboard. Stand usage also better with older smart keyboard.
Nice part about old smart connector set up on 10.5, is either keyboard or smart cover can be paired with Khomo or Poetic simple rear case, or any number of others. I have the Zugu case option also, which I think is the best all in one solution for utility and value, with multiple secure magnetic lap viewing angles
I use my MBP daily in my job as a Budget Director. Very glad I didn't pay extra for the touch bar.
So for me it's the total "package" versus single features..... Good luck.