Please help!

I have the premiere of my documentary in 10 days and it's not finished yet. I'm working full time...but PC's HDD makes weird noises and fails often which provokes computer to restart...I'm afraid HDD is about to break for good.

I cannot risk and I bought a new HDD...but I'm not sure my PPCS6 will work well if I start working in a new HDD.
I've been reading all along and only solution I found it's at "Project Manager"...but there it tells me "Resulting Project size (est.): 330 GB"...which it's just insane.
I'm now backing up the Preview Files folder of the project into the new HDD, but I'm not sure it's going to be enough.

Please! Anybody to put some light into this complicated situation!!
How can I keep working in my project at a new HDD and finish my documentary?

Thanks in advance for your help, it's really needed now!