@Samuel229 Of course it would save you a lot of money- you say that your host has been wonderful, yet you are wanting to cancel 3 and a half months of a 4 month booking and get all your money back. So you don't care at all about the wonderful host? Do you realize your 4 month booking has blocked the host's calendar and that he/she has missed out on all the bookings they could have gotten during the time you held their calendar hostage? So you'll save money and the host will lose money. Not exactly a caring attitude.
Move to your relative's house and pay the $ to the host that you agreed to, according to the cancellation policy that you could clearly see when you booked. Or ask the host if they will agree to let you stay for the month you have to pay for anyway and move after that. At least that way they'll be able to open up their calendar and hopefully get bookings for a month from now.
Just because your circumstances change doesn't mean it's okay for other people to take a loss on your behalf.