He'd be charged criminally, and there would be at least some hearings in court. Whether the vicitm would need to appear or testify varies, depending on the circumstances.
Initially he's going to be arrested and held until at least the next morning. Any possibility she might die and he's not going to get bail. I can't imagine bail of less than $50k and probably in excess of $100k. For some of the court hearings, depending upon the jurisdiction, he would do the hearing by video while in jail. Although the victim could testify at any hearing, the only one where she'd really be needed is the trial.
If they came to a plea agreement with him, where he agreed to plead guilty or no contest to the charges for a reduced sentence, then the vicitim wouldn't have to testify. But if he fought the charges, the it is likely she would have to testify.
This has some serious variety. If she refused to testify, in some jurisdictions they'd drop the case. In others, they'd compel her. And in others, it is no longer necessary (although better for the prosecutor). A plea bargain would not require her testimony, and can be a reason for the plea.
If he agreed to a plea agreement, depending on location, it could be agreed on and entered by the court in a matter of months (I'd guess 6 minimum, but perhaps someone else with more recent/specific info can advise).
Record matters here, but I'd be celebrating if I could get someone 6 months on this these days. Hell, I'd be happy with a year. Drunks are hard to find people to say nice things about them, usually not even their mother.
But if he fought it, he likely wouldn't go to trial for more than 6 months later, sometimes the trial doesn't start for more than a yer.
This is the type of case where if you can stall it, you do. Most defense attorneys believe in the old wine defense. No case should be tried before its time. My record was over five years.
Prosecutor, on the other hand, wants this in court as soon as possible if there is any press coverage.
One advantage of waiting is that the longer it goes on, the more likely the defendant is going to plea.
You really need to do some specific research on the specific plot you decide on to make sure it works.
And for ease of computing all this, it might help you to pick a place where it is set, just for in your head. And remember than could be a large impact on timing and outcome depending on whether this happened in a large city or a small town or somewhere in between.
So, either post more specifics or start doing some state specific research.
~suki