GPT PMBR size mismatch after dd clone

Do as the gdisk prompt suggests: Use the e option on the experts' (x) menu to relocate the data structures to the end of the disk. You can accomplish the same thing in parted or GParted if you prefer. IIRC, they do it semi-automatically, although they ask for confirmation.

Once you've moved the GPT backup data structures, you can resize your partition(s) using GParted.