I love iodine. When you're at a "free" wifi hotspot that needs an account (yet another company to take the security of your data so seriously that they upload it to an open S3 bucket), or you're on mobile data and out of credit, or whatever, iodine usually always works because as you say DNS is almost always allowed.

It's only a dozen kbytes/sec or so, but this is more than good enough for RSS, email, IRC, HN, ...