There are several users that have a similar pipeline: creating characters in CC and then doing the rest in Blender, so there is help for that here. One of them is Autodidact, who regularly posts about this.
As to disk space, it is indeed a good idea to have the programs on C:\ but any content on an external drive. Over time, content can take up a lot of space, so it is good to be prepared for that. You can specify this during installation, so it is important to have the drive already connected and a drive letter assigned. If it is D:\, for example, you would specify D:\Reallusion for the content. You only specify the root (Reallusion), the program creates the rest of the folders.
I have a laptop for iClone and CC with an external drive of 4TB. It is just a regular HD, but with SSDs getting cheaper all the time that is now a feasible option.
Added: Here is a recent thread that may interest you:
https://forum.reallusion.com/475503/Animation-from-iClone-to-Blender-A-quick-test.
Edited
3 Years Ago by
animagic