OK, there is a way to play this. Host your own server! From the original comment:

1. Go to your web browser.
2. Type 192.168.1.1 in the address bar. (different for your specific brand/model of router).
3. Type in the username/password (different for your specific brand/model of router).
4. Navigate the GUI to the Applications/Gaming tab (different for your specific brand/model of router).
5. Enter in the info from the post into the appropriate fields remembering to check to enable and save the specific rules. (UDP 27015, TCP 27015, UDP 27005)
6. Start TF2 :p
7. Open console “~” key (if that doesn’t work go to options/controls/adv-enable console
8. In console type map mvm should see a few maps to pick from there.
9. Server should be ready for people to join after you get done loading the map you chose.
10. Focus fire always on Tanks, Bomb carriers, and Sentry Busters (If engie pick up your sentry and kite them remembering that cool guys don’t look at explosions).

‘course if you’re on a DSL connection remote players may find the game rather laggy unfortunately.