I flew Jet2 to Malta last September and I've got to say they were fantastic. I honestly can't fault them. What really impressed me was, on both flights, having reached our destination we were disembarked row by row. There was no pushing or shoving everyone just left their seat calmly when instructed to do so by the cabin crew. Also, prior to our trip they kept in touch by email to insure we had all the right documents etc. Luckily, you that you no longer need to complete a UK Passenger Locator Form prior to returning home - as that was a bit of a nightmare. Just make sure you have downloaded and/or printed you NHS covid pass and any pass needed by the Portuguese authorities. It all seems overwhelming at first but once you're travelling its actually quite straightforward and far less stressful than it seems to be before you leave home.
Have a lovely holiday, you will be fine!
What gives you a warm feeling? 🥰