My Lexi will be 15 weeks this Wednesday. I bought her two play yards and put them together so she'd have more room.I think my claustrophobia had something to do with that. When I put two together she has about 10 X 6 feet. It easily folds up when I'm home. I like to keep her confined until she gets through the chewing stage so she won't chew my baseboards and trim. So far, she hasn't had any interest in the wood, but God knows what she'll find entertaining when she's home alone and bored. She uses her potty pad while I'm gone, but if she hadn't I probably would have used only one playpen to make her area smaller. I leave her food, water, bed, toys, potty pad and soft blankies so she won't have to play on the hard tile. I leave her bed, potty pad, and food/water in the kitchen where they normally are and put the playpen around those things. That way she doesn't have to adjust to any changes in where to go to potty, eat, etc.
I want to skype her to see how long it takes her to calm down. It might be better that I don't know because if she cries for a long time I'll be devastated! But, yes, it's the hardest thing to turn my back and walk out that door when she's crying.