I can quote the app info on their web page but can confirm that the size control mentioned is available. I have only cloned to similar or greater sizes.
The app will copy a drive or an entire hard disk, partitions , active status and all. The info says it "supports copying of larger hard disks to smaller hard disks". The option is there , as well, to decide how much of the disk you want to use on the clone--you do not apparently need to use the entire disk even if it is smaller.
In your case it may well just ditch some of the data to fit it all in--seriously, I think you ask a rhetorical question since it would appear you know it is difficult to fit in more data than a drive can handle.
haha
probably their resource is to reduce partition sizes, not data.