Getting accomodation a nightmare

I'm in the process of applying for a settlement visa for wife and two kids. I have a job offer in the UK but I'm having a hard time securing accomodation so i can add it to their application. It's extremely hard, almost impossible, to get a 3+ month rental online from another country. I'm thinking less than 3 months won't be accepted. Does anyone know of any way to source such accomodation?

I had hoped to avoid going before them but at this point I'm running out of ideas.

Do you have any family or friends in the UK who could provide accommodation?

The only family i have there is a brother but he lives in Scotland and my job is in SW England.