Be smart about your system setup, re-think the way you operate.
I would never run a computer with only one disk. This simply means your system files and your data files are all on one disk. Mixed up. Even if you part off your one disk with another partition and use this one to store data only, you still have everything on the one disk. This could spell trouble.
If, as you say, you are ready to buy another SSD you might as well keep your current disk to only run your system, buy another SSD (the biggest you can afford, they are not too expensive now) and install this which then would most likely be Disk D:\
Now you can offload all your non-system files on to D:\, and as a side benefit it makes it easier to back-up all your data much more cleanly. It also enables you to swap in and out other data disks as needed. See the link below. You can have a whole library of small disks (and they don't have to be SSDs although small SSDs are so cheap now and non SSDs are cheaper still) Your separate system disk C:\ will also allow you to change Systems (in future) if it is ever needed or desired without compromising any data. If you invest in a Disk cloning program (Acronis) and another small SSD you could clone your system disk for save keeping. I for example always clone at least one new copy of the system disk every other week and when I try new software (like a free evaluation) I do a clone before installing it. If I don't like it I just clone back the original. Quicker and safer than uninstalling which always leaves stuff behind. Cloning a small system SSD takes only minutes.
This is what I use:
Removable Rack Tray for 2 Bays 2.5in Hot Swap SATA Hard Disk Mobile Rack | eBay
Hope I make sense, and good luck.
Cheers
P.S.
With this Disk Rack you can quickly remove the data disk (with all your pictures) when you go on a holiday and hide it for safe keeping.
If some low life knocks off your computer he or she will only have a computer with a system disk.