I see you are in the UK, so I would recommend going for 4-season tyres, rather than the 3-season CCC you have now. Alternatively you could go for a mild all-terrain if you drive on non-tarmac roads much. What size are the tyres?
The Jeep GC need to tyres to be within 10% of each other else your transfer will not be very happy and if that goes wrong your bank account will not be very happy either