All three of our dogs sleep in crates at night.
Holly and Skye usually put themselves to bed before they are actually told to go so that they just have to be sent outside for a last toilet (unless it's really late then we don't bother sending them out and just shut the door) when they come back in they automatically go to their crates.
Lewis' crate is upstairs, if we put him in a crate downstairs then after a couple of hours he starts to whine, if he's upstairs (where all the bedrooms are) he sleeps through the night.
Our dogs are not allowed upstairs (we have a baby gate) so Lewis is carried up at night and down in the morning, so even if Holly and Skye didn't sleep in crates they couldn't go into anyones bedroom. The two reasons for not letting them upstairs is we don't want them in bedrooms, but mainly for safety reasons, I have heard of dogs dying from injuries after falling down stairs (ours are wooden so relatively slippery) and I don't think its good for dogs to go up and down stairs a lot. No playing chase on the stairs.
I think Holly and Skye would sleep in their crates even if the doors were open but there are a few reasons we shut them in.
1) the cats (our dogs sometimes chase one of them, so it's nice to ensure the cat is safe overnight), also, the cats sometimes bring in rats/mice, it's better to not let the dogs get involved in that.
2) we have a cat/dog door so we don't really want the dogs going outside during the night incase they start to bark/find a hedgehog etc.
3) Holly has taken a long time to be trustworthy, she will be really good and then randomly do something naughty (nothing too bad though, just enough to keep everyone on their toes) which we would rather prevent overnight (eg, she chewed up a clothes peg yesterday - she hasn't done that for months, every so often she will decide to climb onto the kitchen table or knock over the recycling bin, but most of the time she doesn't).
So they are all crated overnight. When we have competitions Holly and Lewis have crates in the car. Skye always travels in a small crate (because she is so small). If no one is going to be home for more than 10mins they go in their crates (Lewis has a downstairs crate for during the day) - that's not very often though. They are all very comfortable being in crates.
But in saying all that, I don't think a dog has to sleep in a crate to be crate trained and to be comfortable in a crate. You could shut Evie in the crate once in a while if you want to make sure she is ok with it though.