I'm a big fan of the large playpen we have a dog and I put 14 mth DD in ours whilst I potter about doing housework. I don't leave them alone together so a playpen is ideal when I'm in and out.
DD will play happily for a couple of hours in there but I chat to her as I go past and stop and play for a few minutes every so often.
I love the playpen, and wouldn't be without it.
But I think could NEVER leave her in it whilst I slept, and definitely not in another room, monitor or not.
With toddlers you don't need to worry about them when they are making a noise - it's when they are quiet that there is most likely to be a problem.
Yes I use a playpen. I leave DD downstairs in it, but I listen to her babbling and toys moving constantly and if it goes silent that is when I check she's ok, because she isn't actually doing what I would expect - ie playing with toys. Last time she was playing with a spider! (Eeeek!) But it could mean something more worrying like choking or a fall that has knocked them out.
If you are asleep you are missing the silences, and for me when a toddler goes silent they need checking on.
Plus At 17 mths he could discover how to climb out at any time - what if he'd cracked it this morning, or any other time you are asleep? He could have done anything, gone anywhere and you wouldn't know. Even in the same room.
Playpens are brilliant but you still need to check every 10mins or so. They are an aid to parenting not a substitute.
I believe when DD is awake I should be awake - - no matter how tired I am. She relies on me to keep her safe 24/7 and now she's mobile and I know she WILL suddenly climb out of her cot and playpen one day leaving her awake in either whilst I was asleep and unaware is unthinkable.
FWIW she wakes 2-3 times a night and barely naps. I am knackered. But then I kind of anticipated I would be when I had kids, for a couple of years at least.
Do you have a DP? Could you nap when they get home?
I think this is an accident waiting to happen. He's safe now, but one day he will learn how to climb out and if you carry on sleeping whilst he is awake chances are you will be sleeping when he does.
They don't only tell you to sleep when the baby sleeps for your benefit - the reverse is true... Sleep when they sleep because you need to be awake when they are awake.
Look at it this way - If something (God forbid) happened whilst you were sleeping and left DS alone what view do you think SS would take?
I can tell you. It would be neglect. And that's why you should not be doing it.