hi redbaron-
regarding where your wife could stay after treatment, i would imagine that the treatment facility will know of options available. perhaps share with them that you do not want her home because you are concerned for the safety of the children and see what they propose?
really, tho, it's your wife's problem to solve, isn't it? it is more than reasonable that you do not want her home caring for the children if she has a history of drunk driving. she needs to understand the seriousness of what she is doing and while she is in treatment would be a good time to tell her, because she'll be able to discuss it with her therapists, who i would imagine will support your point of view 100%.