[@John] Partitions need to be contained within a physical drive, cannot span across drives. So there would be no way to use part of a hard disk to expand the “C:” partition on your SSD. I recommend moving or reinstalling the larger programs that you don’t use often to a different drive.
Just as a reference point, I have a 512GB SSD with 2 partitions (plus the recovery and other partitions from my original hard drive). I have a “C:” partition with 344 GB (116 of those are still free) and a “Q:” partition with 106 GB I used for a big fast temporary storage area for faster video and audio processing. Over 1,000 programs installed. I keep all my pictures, movies, music, samples and sound libraries, and my spreadsheets, PDFs and other documents all on hard disk drives. Games (about 20% of the 1,000+ programs) are installed to a hard drive, not the SSD. So far this has worked well. My next upgrade will be a better graphics card, not a bigger SSD :)