I've flown to hawaii 4 times rt in coach and while it sucked it wasn't the suckiest thing ever. the worst part of the redeye home is the landing in hub and dealing with normal travelers all over the damn place while you groggily drag yourself to your connection home. it is possible to get back on a non-redeye but it's trickier and you blow through the whole day doing it. when traveling with kids I am very adamant that we are going to get a LOT of trip out of the travel time. I'd never got to Hawaii with kids for less than 7 nights unless I was rusty and could get direct flights. I do the same for even domestic trips. we're flying to maine in July and staying 8 nights for similar reasons. if I have to fly into freaking bangor and rent a sled to drive to bar harbor I'm getting some time in.
I'm guessing you have booked already, but it is worth the time to fly into Portland instead of Bangor. The drive from Portland to Mount Desert Island is awesome. Eight nights is a looooooonnnnnnnnggggg time for Bar Harbor if you aren't jumping on that CAT Ferry to Nova Scotia for a couple of days. It's really really small but even more isolated. Most of the businesses are either bar/restaurants, souvenir shops, and ice cream shoppes. Last time I went, we went hiking, biking, and Sea Kayaking, all at Acadia. Went mini-golfing and arcading, went to a lumberjack show, deep sea fishing, and an island dinner cruise and did all of that in 4 days, because everything is really close, like you drive there and need to do so, but you won't need the car again for anything but the Lumberjack Show and Mini-Golf, because those two things are on the island but not in Bar Harbor.
I have a ton of Bar Harbor and Maine tips. Maine is my Disney for you. We are staying on the South Coast this summer.