I was lucky, because my husband is a teacher and we got Millie in July, when he was off work. However, we knew that in August he would go back to work, so from day one we did start working with her to be in the crate. He started her in the crate for 1-2 hours. He would work outside - (We have a mini-farm) and then come in and take her to go potty and play with her a little and put her back in for a couple more hours and so on. Every day, he would add 1-2 more hours until he had her up to 6-7 hours in the crate. He would run errands or stay working outside most of the day. so by the time he went back to work he had worked her up to 6-7 hours. When we were both working we had her in there from 6:45am until 4:30-4:45pm when we came home. (We live too far away to come home for lunch; it's a 45 min drive one way). Jim cannot leave the school anyway and we car pool. However, we always came straight home - in the beginning- no detours or errands, no matter what! When we got home, we took her out immediately, for a long walk. (Mostly at that age, she just walked around the property; now she goes up and down dirt roads for her walk) She would pee about 3 times and poo 1 time. We made sure she stayed out until she had her 2-3 pees and her poo. We trained her to pee and poo on command (but this came slowly and over time).
I would get up around 5:30am and would take her out for potty and feed her. (normally, she would do a poo sometime in the morning) I would take her for a 10-15min walk before we left for the day and she would do it then, if I remember correctly. Then we would feed her again when we got home after her walk. She slept most of the day, so she did not exert any energy to speak of and she never had any hypoglycemic episodes, even though she was very small, less than 2lbs.
Even after Millie was house broken, we kept her in her crate at night. I was not real worried about going potty in the house. She had other issues. She would bark at night if she heard sounds and would not bark if she was in her crate. Plus she would wander the house and wake me up and stuff like that. So we kept her in the crate. However, we would have to get up at least once a night to let her out to go potty. She could hold it all day, but when we were there, she always needed her late night potty breaks.
Also as an aside, even though she could hold it all day, when we were not there, she still had to go potty every 1-2 hours when we were home. The older she got the less frequently she had to go, but it's just as it is with any other puppy. The crate does not substitute for your active participation in the potty training process. So don't be fooled that you will not have to take her out more frequently then expected when you are home and that you will have to watch her like a hawk when she is out of the crate and x-pen, no matter what they can do when you are not there.
Oh by the way, Millie sleeps with us now. She sleeps on our bed and her own bed that is beside our bed. She doesn't wander anymore. She still barks, but if we keep her in our room with the doors closed, she does not bark at all. It's just if she hears other dogs barking, she has to get in on the act! She was about 1 1/2 years old before she was given the privledge of getting on our bed. But we had to work on that too. She had slept in a crate all her life, she did not know how to sleep with us. I started her out slow, with naps with me, or maybe only 1/2 the night depending on how irrating she was being.
I would never have allowed her to sleep with us in the begining. She was in puppy Boot Camp and that was too much leniency and a privledge she had not earned yet.