FMP - Development - Portable Hard Drive Size is Slowing me Down

I got the above hard drive over 2 years ago and had never considered using all the space on it, 150GB seemed more than enough given that the hard drive in my old desktop computer I was working on up until only a month had a mere 120GB of storage. 

I know have 1.5TB of storage on my home computer so running out of space shouldn't be a problem for a while. However my portable hard drive is beginning to cause problems in the production of both the Stay Focus music videos and the D-Fusion promo, these combined projects total in excess of 200GB (so I hope the tutors don't want all the development work on disc because they'll end up with about 40 DVD's).

The amount of raw footage we have takes majority of this memory, unfortunately this has resulted in me to keep changing the files on my hard when edited one or the other project. This is made more time consuming due to the fact that I can't just edit one project at a time, as these projects are for clients they need  give feedback on my editing progress.