Disk cloning; need help.

Ok guys, here is my situation: hard disk (500gb) partitioned with win 10 (nearly 50 gb), Ubuntu 14.04 (same space) and data; i want to use my new ssd (250 gb), my idea is, to reduce the data partition to an appropriate size and clone all the allocated memory via gparted or gddrescue (in both of the cases using a live usb); then remove the old Ubuntu to install the newest distro. Am i overlooking something? What could go wrong? Please give me some advices, my last few attempts went really wrong, cause i lost GRUB or could not see win 10 partition.. Thanks