How can I afford London?

I have a job offer to relocate to London. I'm currently in relatively high cost of living area in the US but on 250k I still purchase a 2500sq ft house with a backyard. My London offer is basically a flat move and I want to take it because I've been looking for opportunities in England or Ireland and holy moly where do you even live? I have 3 pets (2 dogs) so I need a backyard. It's not possible for me to live in a small apartment. In NYC you'd live in New Jersey and commute 45-50 mins in but I can't find anything within an hour of the London office (it's pretty central London) that's remotely affordable. Are there areas I'm unclear of, do people just like 1.5-2 hours outside of the city if they need a house?