I used to pay a fortune for expensive roaming packages with EE / Vodafone etc. That all stopped a year ago when Flexiroam (and other eSIM) providers started offering global packages at a sensible price. I’m out of the country for more than half the year but spend only £70 or so on data for the whole time. I just use 3 pay as you go for everything else, and it still includes a decent chunk of roaming.
You realise just how much UK mobile providers are out to rip you off when they’re more than a thousand times more expensive than Flexiroam and more restrictive. Airolo and Nomad are also good providers, but Flexiroam has overall been best for me with the phone hopping straight onto local 5G networks.
A bonus from this is that if you have no signal on your own sim at home, chances are that another provider does have coverage. Because the Flexiroam sim can roam across all UK networks, it’ll generally get data unless you’re truly in the middle of nowhere.
This is my referral link for Flexiroam, gets you 200MB of data to get rolling:
https://roam.my/7KCJ444U
You might need to wait a week or so until one of their big discount codes roll around, which give 25-40% off the standard price.