If I were to take a alprazolam before bed would it help avoid a panic attack in the morning?

Possibly. Alprazolam is a relatively short acting anti-anxiety medication which is why it is given 2-3x's/day. Some people get panic attacks in the middle of the night so it should prevent those attacks but if you sleep 8 hours at night more than likely the effects will be gone by the morning. However xanax (brand name for alprazolam) comes in an xr form that can be taken once/day.
Not likely, As Alprazolam is too short acting and will be gone by the time you wake up.
Xanax (alprazolam) at nite. Usually not, since the half life of xanax (alprazolam) is short, it would be out of your system by morning, unless you take the extended release xanax (alprazolam)-xr . Talk to your doctor about this.