Congratulations Papa!
My kids were not preemie, but I had a couple friends who are preemie moms.
Honestly, If reasonably possible, I'd put off travel until your daughter comes home from the hospital. At that point, they're like a normal baby, but smaller
It will be enough of a transition when mrs hoyateach is home alone with both kids, but at least at that point they'll all be home.. and she won't be trying to divide her time between the hospital, home, and taking care of your oldest.
Having a trusted relative to stay with her is a possibility, depending on the person and how your wife interacts with them ... and you know her better than us. Will having someone else there be a help to her, both physically and emotionally? Or will she try to treat that person like a guest and feel guilty for taking help?