hi, if you disable Windows hybernation feature and, if you have a lot of ram (4GB+), disable Windows paging file, you should save a lot of HDD space.
For example, i have 16 GB of RAM. Disabling the hybernation feature I saved 16 GB of SSD space and, disabling the paging file feature, I saved 12GB, for a total of new 28 GB free SSD space
A SSD is really faster than a common HHD, but it should always be used - in my opinion - with a hard disk as "archive".
If you need a lot of space and you can't afford a 256GB SSD, then you should replace the SSD with the original laptop's hard drive.