I have just settled on the idea that the kids will not have a regular routine. The routine around here is that everything changes pretty often.
I keep a calendar on the fridge for the kids so they can see what "kind" of day is coming up: When hubby and I both work, they go to Grandma's at bedtime, spend the night, the whole following day, and we pick them up in the morning when we get off.
Other times, a babysitter will be here with them when they wake up in the mornings, because we get up to leave so early.
The thing I really focus on is being very intentional with touching, reading with, listening to, and being with the kids when I'm with them.
Sometimes we facetime a couple of times through the day, and they are always allowed to use the sitter's phone and text me. I can usually respond to that in a whole lot of different situations that a phone call is not appropriate.
Even my littlest, the 2 yo, loves texting. She think's it's amazing when she dictates something to her sisters and I reply back with the right answers.
Make sure that he has everything he *needs*, don't stress over stuff he *wants* and make sure that he knows you love him passionately, and nothing can ever change that. That kind of love covers a multitude of issues, and kids are resilient and get used to things pretty quickly.