I plan on DS being in cot until 20 months or there abouts and then putting him into a king single.

As this way he doesnt get moved out of cot as soon as new baby arrives but also sees baby in bassinet and then after 3 - 4 months into cot, by this stage he should be happy in his big boy bed.

My other issue will be he has been in grobags since 9 weeks how do kids go whne put into a bed with a doona. As currently he is always warm and can move where ever he wants.