Alright for the packing,
just pack a small overnight bag, that has your overnight things in it + harley's food/bowl, and water.
Try to make only one trip into the motel room carrying things. I try to get a room by an exit door, cause if you have to do a middle of the night trip out with your dog, voila the door is there.
I also preplan my motel stops, I select motels that is say 2 hrs before from when I'd like to plan on stopping, then one hour away, then the motel at the planned stop. You never know how tired you will get on the drive, or how much traffic you will have to deal with.
If you are a member of CAA, they can plan a road trip for you, and then you will get a great mini book of routes, motels etc.
As you might already be aware, mainly Super eights, Motel six's take dogs. Comfort Suites does too, but that is a pricey stay.
I love the roadside stops, and try to find what ones are along my route; CAA is good for that too.
With the I phones etc, you can usually quickly look up a vet near to the area you will be staying in.
First Aid Kit for the car.
I usually get sick of hearing my GPS, so what I did was Print OUT in LARGE PRINT my route, and scotch taped it to my dash. Worked like a Charm.
If your GPS is anything like mine, I also take Maps along with me, as the GPS has lead me astray on more than one occassion.
I plan on a short stop for the pups ~ every 2-2.5 hours. Then one long stop for lunch and a 30 minute exercise session. We all like to play, and those roadside stops are great for that.
Car charger for your phone.
I bring my water from home, then when I run out, I buy the spring water.
I hope you get cooler weather for the drive, cause it is a real pain when you have to go to the washroom and you must leave the pups in the car!. What I did in a pinch when we were travelling to Missouri, is at one of the roadside stops I tied the big dogs up to a big picnic table, and placed Razzle between them in his crate. Then I set the record for the fastest washroom break!.
Books on tape are great to keep you occupied.
Of course some driving tunes.
I should be in town the last week of August. Stay safe on the road!
Also I always try to stop before dark. I personally don't like going into strange motels in the dark. Be aware, just like you would be in a strange city. For me I hide and keep some cash, credit card, and my debit card, underneath or inside Magic's crate. Now that won't work for you
But you could try some other hiding spot. I carry my purse(actually I use a fanny pack sitting in front), when going to washroom, buying supplies, whatever. This way if I get held up hopefully I only lose what is on me.
Also your spare set of car keys, I use one of those magnetized boxes to put the extra set in.
I usually pack my lunch for the following day. I leave home with a cooler stocked up with fresh fruit, salad stuff, cold meats, and of course the doggy food
Keep safe, and have a great trip to TO.