I don't know how old are you younger kids? you may be able to do foam sticker projects with them. While they work on there's you work on one for your oldest. The phone isn't the only way to communicate. Get a bunch of post cards put them in your night stand(or suitable place your at for down time) and a pen. Pre stamp & address them to make it easier whenever you remember write a little note and send it. Get pre-paid flat rate boxes and when you see something she'd like that you would get for her if she was with you pick it up and when the box is full send it.

just sitting w. kids while they play and talking about what they like is enough for them. Bed time story and family dinner are very important in my family. Best of luck.