Agreed with your concerns. The fact that it was widespread and no action from Tesco that indicates any understanding of what was compromised suggests they have

Agreed with your concerns. The fact that it was widespread and no action from Tesco that indicates any understanding of what was compromised suggests they have no clue. So they may still be vulnerable. If UK customers can find a low (or no) cost alternative place to put what remains of their money, I'd do that now. This might not be over. They may not know how the attackers gained access or if they're still inside until incident responders have done a full workup on the network.