Annoyingly, I recently threw away a free Smartie SIM, or I would have sent it to you.
I do have a Three SIM in a router, but the credit on it has probably expired so probably easier to get a new one.
Ofcom reckons you have ok Three coverage as well, you could try getting a SIM (eg: https://www.idmobile.co.uk/shop/plans/pay-as-you-go/sim-only) and seeing if the coverage is any better.
Annoyingly, I recently threw away a free Smartie SIM, or I would have sent it to you.
I do have a Three SIM in a router, but the credit on it has probably expired so probably easier to get a new one.
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