Hello again, sorry I was in production and couldn't make it back to my edit station to verify my process. So the multicam master clip and multicam sequence are 720X405, which was linked to proxy files of the same resolution. After cutting the sequence and several rounds of notes, I relinked the media to the originals, all 1080p.
Now the media in the project is all 1080p, but the sequence is still 720X420, so the window is restricted to a small portion of the actual frame. If I match frame and paste into a new 1920X1080 sequence, it remains small because it cuts the multicam sequence (720) into the new (1080) sequence. Match frame and overcutting adds the multicam sequence (720) to the new 1080 sequence because it is nested adn cannot be collapsed/released etc... Disabling multicam on the clip changes the camera selected so I lose the angle but retain the frame position in the sequence. I have an inkling this is where my solution lies, if that makes any sense, but I still haven't got it yet.
I can manually and visually match frames with the originals and overcut, (time-consuming and less fun than other things but, whatever works) however it is difficult to judge the frame because there is a limited view of the frame after reconnecting the original 1080 footage.
Sorry if this is confusing, I hope to be clear and appreciate the help! I've looked around in help and forums and as far as I understand, there is not an easy solution to this yet. So you could be the first to help and we could spread the words of hope. 
Any other information I can add please let me know. Thanks!