Toddler moving to upstairs bedroom

Due with my second in March and planning to move my toddler to one our upstairs bedrooms in January to hopefully soften the blow of having a new baby take over his old room.

I’m just curious how people have this set up. Our room is on the main floor next to the nursery. Of course we will have a monitor. He is still in his crib (he still loves it so I’m not questioning) but when we do move him to toddler bed, how do you use child proofing to keep them safe up there?

We have a gate at the bottom of the stairs and a door at the top. Should I just put the childproof doorknob devices on? Do you put them on the inside or outside of the room door? Should I put a gate also at the top of the stairs?

I also worry about the ease of getting to him in an emergency…