No, I just have a dual-sim phone(OnePlus 5T) - for data and calls in UK I have a proper British sim. But whenever I need to call my family or anyone in Poland, I just dial from the second(Polish) sim, and call for free, using the minutes that come with my Polish contract(and they can call me for free on my Polish number as well). It's also pretty useful whenever I'm somewhere in the UK that doesn't have a good signal on my main network - then I can use the Polish sim to connect to any network that has the best signal and just use data off that card temporarily.
Well, yes, it remains unseen what happens once brexit actually happens. But this solution works at the moment, and I can only imagine it can also work in other EU countries.