We will be in the UK for a few days, then France and Spain for 3 weeks. In the past we have had bad luck with our phone carriers International plans as well as SIM cards in the UK and Ireland. I am wondering about an eSIM. We will need data for maps as we are driving in France, we also have WatsApp , I'm wondering if an eSIM might be the easiest to get uploaded before we leave and with a high data limit we could do all the texts and calls we need to make. Perhaps a data only eSIM? What brands of eSIM are easy to use and reliable?
With UK outside the EU now, you may need 2 solutions.
There is already several informative threads on eSims in the Technology section. https://community.ricksteves.com/travel-forum/tech-tips/buying-an-international-esim-data-plan-for-your-regular-phone-with-esim-no-more-burner-phones
I haven’t had any issues using either Vodafone UK or EE. The customer service agent has always set up my phone and usually it’s working before I leave the shop. Inexpensive plans that work for me. If you want to give it a shot then EE still offers free EU roaming on their pay as you go plans. I seem to recall that three UK will ship SIM cards to the US and offers EU roaming too?