Pre tournament camp in Portugal

So this may be a question to the sports science people in the sub but here goes;

What are the advantages of warm weather training camps like the one in Portugal at the moment? Is it like the high altitude training long distance runners do?

The reason I ask is that what I can see from social media is that they are working out, running plays and generally training which is things you expect to do at camp before a 6 nations run but why do it in Portugal and not the IRFU center in blanch?

Also, it can't be cheap sending 50 or so players and coaches over there after reporting an 18 million euro loss last year.