Best of both worlds

I have some friends, and im sure there are more of them out there which 'commute' between london and the algarve. They work there in London, monday to thursday or friday and then come here for the weekends. I found this quite strange at first, I mean I have heard of people moving to norfolk or such and commuting to london but to a different country, hmm. But they have the best of both worlds, they carry of doing what they do with their salary levels and have the good 'foreign life'. I would find it very tiring to do this and you must start to feel like you speand all your time in airports, no matter how quick you can travel (without hand baggage etc). But good luck to them, I hope it works in the long run.