I'd love to hear some stories and experience with transitioning a 21 month old (or thereabouts) toddler into their own room. The reason I'm considering this is because I've started putting the baby upstairs (in the family bed) in the evenings (as opposed to holding her for the first few hours of sleep as I had been for many months before). What I noticed is that she seems to sleep better (often) when she's alone in the room. I would eventually like her in her own room and perferrably sooner than my first child made the switch so I thought maybe I'd try.
My thought would be to put her to sleep there and feed her there for her first waking (usually 2-3 hours after she falls asleep) and then see from there. I may try to feed her in her own bed for the second waking and wing it from there. I'm sure there will be at least another year where she is in with me for at least a part of the evening/early morning, which is totally fine.