I have been in this situation twice but without physical violence, the second time I went to a refuge and met many women who had experienced much physical violence but all of them would agree that it is the emotional abuse which is most damaging, Both of my husbands would have considered themselves christians but both of them had extremely damaging behaviour. What I feel is most relevant in this situation is not whether the woman would survive physically but how the effect on her emotional health would affect her relationship with Christ.
After my two husbands I was recently engaged but again I started to spot abusive tendencies in my fiance, I am pleased to say that the relationship ended and that on this occassion I was able to accept Christ more fully into my life then ever before which resulted in me becoming fully born-again, adopted by Christ. I would never risk letting an abusive man affect my relationship with Christ again no matter what the circumstances were.
What a lot of people do not realise about violent men is that they have a mind set which is very, very deeply installed in them and that they are natuarally very controlling, let me tell you that they will not tolerate anything that stands between them and thier control of thier wife...and that includes the wife's love of Jesus.
If an abusive man wants to get help to control his thinking pattern I would suggest he does this aside from any alternative motive other then his own spiritual or emotional well-being. Having known 3 people who worked with purportrators of domestic abuse this decision may well be long in the waiting. There are some cases where the woman does stay and the situation abates and the coupld are reconcilled in love but statiscally speaking these are so rare if you look closely at it. I think each case must be looked at on it's own merits. Remember, these women are not being beaten for their faith, they are being beaten because of someone else's ego problems. Jesus suffered in a righteous way for righteousness sake but he also ran away from situations when it was not the 'right time' for him to be caught.
Can you imagine any of the disciples being encouraged to stay in a situation where they were beaten purposelessly? A woman has as much right to uniterrupted christian service as any of those men do and in fact, she may even go on to serve the congregation very usefully if she became free to do so.