OP, I think you should go for it! If you had 3 under age 5, then I would hesitate, but your older 2 should be pretty self sufficient in entertaining themselves. I agree in making your first day of driving a little shorter and taking frequent breaks!
I'm a SAHM, too, so the drive and hotel situation is pretty much "just another day" kind of thing for me. At least you will all appreciate the change of scenery

Have a great trip!!
Edit, driving 14 hours and staying in a hotel isn't something I do all the time. But handling the kids on my own *is*. Just wanted to clarify that. lol!