We're due with number two a month from Saturday. DS will be 21 months in a few days. Daycare has suggested moving him into the two year old room starting next week. We're not sure what would be best. On one hand he's doing really well in his current room and he has some time before he's actually two. On the other hand we think it may be good to have him go through the transition before our LO gets here so that he's settled into the room by then. We weren't sure if moving him in a few months, when our new LO is also a few months old, would be more of transition because things are different at home as well.
Re: Moving DS up at daycare
Our daughter began her transition into the 3-5 year old room (it's a Montessori program) the first week in May, and her baby brother arrived on May 11th. It was a lot of big changes all at once -- the toddler room she was in had just 9 kids and the big kid room has 18 -- but she's done really well.
Do they do the transition over a few weeks to get him used to it? I think that helps. If I were you, I'd do the transition now before baby is here.