I did this with my BFF and our kids two years ago. It was a crazy day but we had a blast! Between us we have five children, ages 5-13. We started with rope drop at AK. We took Uber just to be able to start our day a little bit later. We went to epcot then DHS next, finishing up with closing MK. The older four, ages 8-13, were great the whole day. The five year old was a trooper, but pooped out at the end of MK. That was kind of a bummer for my friend because she had to sit with him sleeping the last part of the night, so that's something to consider. Even still we all had fun and don't regret it!
I don't think it would make a great first visit to WDW. But we have all been often and were okay with FPing our favorites and just going on whatever had a short wait, realizing that we would not be able to ride everything we wanted to. And we just had fun being together and experiencing the magic! I hope it works out! Have fun!