When I first moved in, I was lucky enough to be accommodated by two wonderful ex-colleagues from Greece (anonymity is their middle name), that had already settled in London months earlier.
They both left our country as well and came here for career development purposes.
It’s quite a relief to know that there is a warm bed (or sofa :P) and bath in a foreign city you just came in and you don’t need to rush and take impulsive decisions when in regards to home renting.