Forgot to add, I do have the latest version of Adobe After Effects CC 2015.
I took it from 206MB to 56MB using a different codec (H.264 to .wmv) perhaps this will help?
What? No. That is the opposite of helpful. You want more data - not less!
Try transcoding the original footage clip (using the Adobe Media Encoder) into something like QuickTime with the Photo-JPEG codec. Then try running your track on that. Also, what exact version number of CC 2015 are you using? We've had a lot of people lately saying they were running the "latest version of CC 2015" when they were running 13.5.0 and that is NOWHERE NEAR the latest. You want 13.7.1 if you're on a PC (but I'm just having to guess at that since you didn't even mention your OS...)
I am running Windows 10 OS and version 13.7.1, as for your solution I'm trying that right now.
You need to be very careful with camera tracker because it's a real resource hog. If you have a 47 second shot and you are going to have one 3-D element placed in that shot for the entire duration then you will have to Camera Track the entire shot.
On the other hand, if you have a 47 second shot and you're going to place one 3-D element in the first 4 seconds of the shot, another 3D element is going to be in the shot from 20 seconds to 34 seconds then you should split the shot up into the 4 second section and the 14 second section that need 3D elements added to them and track each separately. Camera tracking is like rotoscope, it is horribly inefficient to track anymore of the shot than you absolutely have to.