Buenos Aires
It’s a major metropolitan city, so you’re never too far from someone who speaks English.
High-speed internet is available.
Argentina itself is not super vegetarian friendly but like I said Buenos Aires is a major metropolitan city, so there are options there. It’s also only like $20/day for a private chef.
It’s as progressive as you’re gunna get for your budget. They’re Catholic and very white but they’re gay friendly.
And yes you could live there on $10k-$15k per year.
Colombia is not vegetarian friendly or progressive except in Bogota or Medellin. OP could still probably get by in one of those on $15k/year though.