There are some fairly strict laws on the transportation of human bodies . Unless you happen to die in an area that has a " Green " cemetery , you may be out of luck ....
I've signed something that certifies the donation of my organs in case I die for sudden unnatural reasons. Other than that, maybe I'll donate it for scientifical or medicinal education purposes.
My survivors can do anything they wish - bury, cremate, donate to science - whatever - it makes no difference. Since my soul will be in heaven, it doesn't matter what happens to my body.