Currently, my fourth grader is in Bigger with the fantastic extension package (loving it!!!). This was our first year with HOD (a trial run

I would like to put them both into HOD next fall, but we're expecting a new baby end of May, and I also have a 3 year old (soon to be 4). With a new baby and the 3 year old, I want to take on as little stress as possible...if you know what I mean.
So, here's what I'm thinking.
FALL 09
5th grader: Preparing (with extension pack for 5th graders)
2nd grader: Beyond ????
I didn't really want to do Bigger with my second grader because I'm doing Bigger NOW with my fourth grader (extension pack included

Does this sound doable with a baby and a toddler??? Any suggestions?
Thanks a ton!