A probelm with going from the first WoC to the 2nd F!, is when you leave DCA and get into DL a lot of people are also leaving F!. Adventureland is a huge mess so you have to go into the hub and then meet the people leaving the first F! trying to squeeze into the hub.
To do this.
Watch WoC from a top tier of your color or viewing zone. As soon as it ends get out of the park quickly. This way you are stucking with a few thousand other guests also heading to the exit.
With luck, this doesn't always work out. When going into DL look for a train around the station above. A couple times I've gone through the turnstyle and the train was just coming to the station. So I got on and went to the New Orleans Station setting me up to just fill in the spots that the first F! viewers left. Because of trains not running or not space to get on the next train this isn't always reliable, but works great if it does.
Otherwise keep right and go down Main Street and the fireworks should be starting around now. Go counter clockwise around the hub all the way in front of the castle and into Frontierland. Squeeze into Frontierland staying right keep going around RoA to you find a good spot to watch from.
I can't imagine that you can make it from WOC stating at 9pm to Main Street at 930pm to see the fireworks.
I've done it many times.
The key to doing is as I mentioned above. Watch WoC from the back of Paradise Park and as soon as it ends get moving to the DCA exit.
When you come into DL Fireworks will be just about to start. So take any spot you can which is easier or harder depending on crowds that day. Traffic will be routed into its counter clockwise rotation around Main Street and the Hub. So keep right.