I spoke with CSU about this in 2005, when one of my mares was given very low odds for surviving a colic surgery. They were very informative and I was able to coordinate with the therio vet at the University where she was hospitalized.
Our plan was to remove the ovaries at the time of death and ship them to CSU where they would handle the oocyte recovery and fertilization. Any embryos were to be placed in recipients and I would purchase the mares who checked in foal at 30 days.
I was surprised at how reasonable the estimated expense was. I think it was about the same as a normal ET or possibly even a bit less. The odds of getting a live foal were pretty decent. However, they did tell me that it was good that the mare was fairly young.
My mare made a full recovery, so I can’t tell you much else 
CSU was great about answering questions and helping me make sure we would have the best chance of success. If I am ever in a similar circumstance, I would not hesitate to contact them.