It sounds like you get to spend some amazing, quality time with them most of the time. Look at this travel as a wonderful, cost-effective way to enjoy being an adult, see some new things, eat out, sleep alone, etc. And be soooooo excited to come home to your wonderful family!
I now work at home, but when my oldest was about 1.5 or 2yo, I had a 2day conference a couple of hrs from home. I was nervous. He was with Daddy and did fine. I had a great conference, enjoyed meeting new people, ate a hot meal with other adults, and slept so soundly that night. And I was sooo excited to spend time with them family when I got home! It was wonderful and I told myself to do it earlier and more often the next time.
Time away can be very good for all. It soounds like you have a good plan in place for kids. It will be great time with grandma and good for dad too! Relax and enjoy!