I have thought about your question, and I have found a few answers.
I have a PUG, and my parents are at work all day, and I am at school. He stays in the house, so he dosen't get cold. He is just fine in the house by himself... I kinda think he might like it... since a pug is my breed of dog, maybe I am just egxaterating (sp), but I think a PUG would be the best for you. Also I can find a website where you do a quiz, and then it tells you what dog is best for you.

If you are more interested in cats, then I do not know. I love cats, but I'm not to good with cat breeds.
Good Luck!