Clean break or split for parts?

Hi all, a couple of years back I built up a Cannondale CAADX frameset to be used as a bit of a stopgap gravel project – I stripped it to bare aluminium, resprayed it matte green, and fitted it with a solid spec (Shimano GRX810 1x, SRAM Force carbon cranks, Hunt wheels etc). It’s a bit tatty now but rides really well and I’ve ended up using it way more than expected.

I’m now looking for something higher-end and more capable that can replace both this and my XC hardtail. My question is:
• Do I sell it complete and start fresh? What would you price it at?
• Keep the groupset and certain parts and build around a new frameset (if so, any suggestions?)
• Or break it up and sell in parts (less keen on this as it’s time consuming and can get messy)

Open to ideas – just want something that rides beautifully, looks clean and understated, and feels like a real upgrade and can handle a bit more than this is capable of.

For context I’m in the UK and have a road bike, so its replacement doesn’t need to be anything too “fast road” oriented. I’ll probably this as my winter (road) bike though so no bad thing if it can hold its own on the tarmac. Budget for a full new bike is around £2.5k or £1-1.5k for a frameset if going that route.