Sleeping situations

So recently the girls haven't been sleeping well in the pack-and plays. We have a play yard that we use to keep them somewhat contained because we have 2-3 bedrooms worth of stuff in a 1 bedroom so nowhere to set up the cribs yet. Our lease is up in August and we are getting a bigger place. So what I was thinking was temporarily popping one of the crib mattresses into the play yard and seeing if they would sleep together. They haven't slept together more than a handful of times so I'm not sure how well it would work. But I'm also not sure what else to do at this point :(