My husband & I have a 4 year old Beagle who won't sleep through the night.
She stays in a crate during the day while we are at work and she has slept in our bed at night since she was a puppy.
She wants to leave the room and go downstairs to check things out, drink, eat, etc. several times a night. We have a dog door but if we do not go downstairs with her, she will sometimes pee in the house.
We have tried putting her in the crate at night but she whines a lot and I feel bad because she spends most of the day already in it.
We have a 17 month old son who sleeps through the night but our dog is keeping us up all hours, please offer some advice!!

Beagles are very energetic dogs and need a lot of stimulation and physical activity. If you don't meet those needs they can become destructive or whiny.

How often do you walk your dog? When you do go for walks how long do you go out? Does he have a yard to run around in?

How long is the dog in the crate during the day?

It sounds like the dog may be sleeping all day while you're gone, because there's very little else to do in the crate all day. Could you find someone that's willing to come over during the day, take the dog for a walk and play with him for a while? That would help.

The peeing in the house may be do to lack of companionship and exercise as well. He's trying to tell you that he's not happy. More exercise and I have a feeling the potty issues may go away. If they don't, you have to start from scratch and retrain.

A long walk before bed, a play session, should tire him out enough for you to get some sleep.

Good luck. :)

Is this a new sudden thing? Or has this been happening for 4 years? If it is new, have your vet check out your puppy for an infection.

Alty I have to spread it.

Lacey, another point I want to add. If it is not an infection as JD suggests, you made a comment that he goes downstairs to eat and drink as part of his nightly ritual. If your dog is allowed to free feed & drink at any time of day or night, it stands to reason he will need to potty at some point. And it appears he is doing just that. You have created a schedule that is forcing him to be nocturnal which is not healthy for any dog.

Dogs are creatures of habit. As Alty pointed out, you have a breed that needs a lot of exercise and stimulation during the daytime. If he is crated all day, he is going to do all his exercising at night. You do need to find someone who can give him a really good romp at least once during the day while you are gone. You or your husband need to do the same prior to leaving for the day and when you get home. He should also should be on a regular feeding schedule which always helps set the potty schedule. I usually break up the feeding schedule to two meals a day, one first thing in the morning and one no later than 6 p.m. Allow him free access to water during the day but pick up the dish by early evening. I pick it up by 7:30 pm. The last walk should be before you go to bed to ensure he fully empties bladder and bowels and ensures he will easily be able to hold out until the morning. So, if you go to bed early, pick up the water dish earlier.

Some great suggestions above, I just wanted to add my 2c.

I personally would think about leaving her out during the day. You can buy baby gates to confine your dog to one area of the house where they won't destroy things. I use my kitchen dining area and just put a baby gate between there and the living room. I have a removable one, no screwing and damaging walls, it just has little rubber stoppers you clamp against the wall.
If she is sleeping all day while you are at work and being confined to a crate she's saving up all that energy for night time. But if you leave her out she has the option of playing with toys (you can even set up some challenges for her) and just getting up and walking around.

I always crate at night, it makes the dogs feel secure and when they go in their crates they know it means bed time.
I use wire crates (not a fan of plastic ones at all) and cover them with a blanket.
The blanket makes them feel even more secure plus at first light they aren't up barking to be let out because it's still dark in their crates.