Cheers Chris
As it happens, I came across this website after posting here and I've downloaded an update onto a USB drive. I'll have a go at updating the map tomorrow.
I've also tried seeing if any updates are available on the 'uconnect.com' site, but when I put my VIN in the box, nothing happens. I then press 'enter' again and it says there's an error with the VIN. There isn't because the VIN got me access to the map update on the 'mopar' site.
Any ideas?