The problem you are having isn't one there is a work around for. When creating an RCP recap creates a temp file on both the C drive and the drive the scan data is on of anywhere between 4 and 6 times the size of the file you are importing. This means if, for arguments sake, your scan is 250GB that temp file is upto 1.5Tb. And if your scan is on C drive (my understanding is that) that temp file could be up to 3Tb. I ended up getting 2x3Tb HDDs to do my recap importing on because of this.
The good news is that it should take less than an hour to ug your c drive HDD (once you know how). I can't recall what it is called, but i can find out for you if you want to know, there is a program that you can download and it will clone your C drive. It was super easy to use and all you have to do is clone your c drive to the new larger drive and then take out the old c drive or swap the drives. Your computer reboots like nothing has ever changed except for the fact you now have a heaps bigger c drive.
A couple of warnings though, please do a back up first. Just to be safe. Also 3Tb drives are only recognized for C drive on some configurations. I can't recall what it is that stops it at 2Tb. But a quick google should tell you. Also if you are going from a SSD to a HDD you WILL notice a HUGE difference in speed. So don't panic. (Like i did at first until that one dawned on me.)
If you are interested in upgrading your C drive i would be happy to look up a few things to help fill the gaps if you want. I am on my phone and can't be bothered right now is all.