Q&A: can a pack 'n' play be a crib?

Jennifer writes:

"We moved from Brooklyn to a small university town in the Rockies. While we live in the sticks, the advantage is that we can afford a 3 bedroom house.  We (me, my husband, and my baby girl--and maybe our dog, but she'll probably be staying with the Grandparents in Florida since it's hard enough to find temporary housing for people with 2 legs) will be relocating to Washington, DC in January for a period of 5 months--the baby will be 14 months when we pick up to go. Having lived in NY for a number of years, I know that we're not going to afford the same size housing that we currently have out here.  I'm thinking that on our paltry-western-non-union-salaries, we'll probably only be able to afford a 1 bedroom in Our Nation's Capitol.  Anyway, currently, at 8 months, our baby sleeps through the night in her own room in her own crib.  Here are my questions:

1.) What do you think it will do to her sleep if she can no longer have her own room?  In some ways I wish she had never moved out of our room, but she has so what to do about the impending change?

2.) Because we as adults feel that we can make due with anything for a period of 5 months, we're not planning on buying much more than a futon and a table/chairs (unless we can find a suitable furnished sublet) while in Washington.  Do you think it would be OK for her to have a Pack and Play for a crib for these 5 months?  This is what my husband is proposing, but I'm not sure a Pack and Play has sufficient support for 5 months of sleeping...."

I initially read that part at the end of the first paragraph as "non-Western-Union salaries" and was v. confused. Ah, reading comprehension. Anyway.

In your situation I think I'd "rent" a crib by buying a used one* on Craigslist and then flipping it (again on Craigslist) when you move. I don't know that a pack 'n' play (I believe it's called a "travel cot"--a collapsible playpen/cot--in countries that aren't the U.S.) is supportive enough for long-term nighttime sleep (although I'm sure plenty of kids have used them for just that and sleep fine and have no back problems). But my real concern is that your back is going to be shot from bending over to put her in and take her out all the time--the p'n'p is really low and it's going to be a whole different set of muscles than you use to put her in and out of the regular crib. Also, it'll be nicer for her to have the same sheets and stuff in the crib to make it as similar as possible to her current crib.

I think her sleep is going to be shaken up for a few weeks from the move, so there's no way to tell if the shakeup will have anything to do with her being in your room again or just the adjustment of the move. It doesn't really matter anyway, since the treatment for both problems is the same--as much one-on-one time with the two of you as possible, regular routines, plenty of exercise to tire her out. And her sleep will probably hit a huge speedbump when she's around 18 months anyway, so don't be scared if it happens--she'll go back to sleeping eventually.

I think you'll be pleasantly surprised at how much space you afford (relative to Brooklyn prices), especially if you don't need to be actually in the District. DC-area readers, where should Jennifer look for an affordable but commutable and safe sublet for 5 months?

*Don't get worried and start sending me to the JPMA site. I didn't mean "used" as in "from 1974, with lead paint and wide slats." I meant "used" as in "bought in 2004 and conforming to all current safety regulations, but their child just switched to a bed and they need the crib out of their apartment."