When is your wife's spring break? Would you rather go solo?
I understand your thoughts about what to do if you have an accident and are alone, 9 hours from home when it happens. This not a small thing to consider.
You'll want to plan your calendar in order to avoid spending a lot of time on blue cruisers when there are crowds.
Skied-off New England blue cruiser-groomers can be quite off-putting. The snow turns to ice. If there are people gaining on you from behind, on that icy surface, that's taxing.
No matter where you go, you'll want to get the info here on which weekends to avoid because of New England school vacations. The weekend leading up to President's day and the week including it is always CROWDED. Do not go then.
Any weekend at Okemo or Stowe will be crowded. Probably the same at Killington. Okemo may be the worst for weekend crowds.
Try to ski only Sunday-Friday in order to avoid the worst crowds. If you only ski groomers labelled green and blue, and you're hoping for grippable snow, you'll want to plan to be on the snow when the crowds are not there so the snow is not skied-off by 10:00 am. So timing is important.
Also, if you only ski groomers, I'm going to disagree with others about Mad River Glen. The groomers are mostly connectors between bump runs and wooded skiing. There's a side of the mountain with open groomers, but they have not much snowmaking, so that terrain may be flat, thin, icy, and ungroomed. My suggestion is to ski Mad River Glen once you have spent some time in the bumps and have discovered you like them, even when they are icy.
Killington has more variety in its blue groomers than Stowe, IMO.