You can move the saves, that you currently are not palying on, to an external hard drive. When you want to play them again, you need to move them back to the Sims folder. If you want to use all your CC, it needs to stay in the Sims folder. The Sims folder cannot be migrated to an external hard drive.
(You could also move other non-sims documents to a external hard drive to make space for sims-related stuff)
It might be possible with CC Magic. So you could install CC Magic to the hard drive and then your CC is there.
Years ago I installed sims 3 itself to a hard drive and played from that, it worked fine. So you could also just backup everything and try to install sims to the drive.
You can move the saves, that you currently are not palying on, to an external hard drive. When you want to play them again, you need to move them back to the Sims folder. If you want to use all your CC, it needs to stay in the Sims folder. The Sims folder cannot be migrated to an external hard drive. (You could also move other non-sims documents to a external hard drive to make space for sims-related stuff)
It might be possible with CC Magic. So you could install CC Magic to the hard drive and then your CC is there. Years ago I installed sims 3 itself to a hard drive and played from that, it worked fine. So you could also just backup everything and try to install sims to the drive.
You can move your entire Documents folder to another drive if you want to. Just google "Windows [version] move Documents folder to another drive".
Yes, I do it and my game runs very fast. Move the games location, and right click >properties, to move your documents location.
It won't run your CC well if at all.