R.C.
Hello J.,
I work full time (before and after 2nd baby). My 3 yr old son is in f/t daycare. When I was home on leave with the new baby, it just happened that the first 2 weeks his center was closed for the holidays, so my husband and he just spent a ton of time together. When they opened up, he went back. I think that you may find that 4 days together is plenty when you have the new baby to bond with and care for. You can always do late/early drop off/pick up, to get a little more time as a family, but I was able to actually keep up with the house and meals and make things feel like the baby hadn't really disrupted things. So I got lots of one on one time with my new baby, like I'd had with my son as a newborn, but also was able to keep things feeling calm and consistent at home for my older child so he got lots of one on one. I think that toddler/preschoolers are at an age where they are usually enjoying their experiences at school and he will appreciate having his own routine not disrupted; at least that is how it was with my son.
Best wishes and congratulations!