I didn't use a crate but have a evenflo Happy Camper portable playpen that nathan plays and sleeps in and it works great for us. When i first brought him home it was huge in my opinion but had enough room for his bed, water food and a wee wee pad and play area...now at 8 months( and all of 3 lbs) he just has his food water and bed...he will not soil the playpen but will wait for me to get home if I have to go out for a couple of hours and can't take him. He is safe and when we spend the night out with friends it folds down goes in its carrying case and we take it with us! And he is right at home!!! No problem at bedtime...he goes in and he knows its bedtime and at 6am he barks to let me know its time to go potty!!!
p.s he doesn't sleep with me cause I am not a stay in place sleeper and I am afraid I would squash him!!!
lol