Like you rightly pointed out, most drunk drivers don't have enough finance to cater for the welfare of children that lost thier parents due to the actions of these drivers. But a special insurance coverage for such incident can be introduced. Maybe such cost or responsibility can be transferred to these insurance companies.
So you want to have a mandatory insurance coverage for such incident and then force everyone who does not consume alcohol should take the insurance which is unfair. If you are drunk and if that cost a life then you should be responsible for the actions and i am an advocate of that but to have a special insurance, do you think any insurance company will take any high risk insurance like that.
I am thrilled by this innovative discovery called breathalyzer, it would prevent these careless accident, in fact all carmakers should be mandated to install them in every car produced.
I do not want to see a breath analyzer being installed in every car but strict actions should be taken against anyone driving after consuming alcohol.