Hi wqroo
Like enmus Iβd replace original SSD with a bigger one. Install the Qubes from the scratch safest. Or could try use qubes backup before SSD replace and qubes restore after fresh install to new SSD.
Looked at NitroPad X230 | shop.nitrokey.com under Hard Disk (SATA) up to max 2 TB SSD options listed. Brand and model not said. In past Sven recommended
When I find money tree hope get professional grade SSD. My $0.02
btw @wqroo welcome to forum!