Who says they can't see the URL? A sufficiently motivate government would probably be able to create forged certificates and mass interception isn't really out of the question. Especially with browsers homogenizing on fast ciphers AES-GCM/POLY-1305, I bet it's much more economical than you would think.

Cert Pinning or HPKP is one type of solution, but it's tricky to get right especially for a large site like wikipedia.