Have just got a bfp, although it's very very early days. DS 1 will be 2.7 when dc2 arrives, all being well. Have just told my DM and she has let it be known that she thinks I'm going to find it a struggle 
I know that going back to the newborn stage is going to be tough, and opportunities to rest will be greatly reduced with a toddler around. I know that there will be a period of adjustment while ds gets used to being a big brother.
Realistically, how much harder will it be?