We loved Acadia and The Kank. We were lucky to see some leaves and just had s very nice time. Since it was later in the year (after your planned visit), there were no crowds.
If you do make it to Acadia, agree Jordon Pond House is very nice as are the carriage rides. We stayed at an AirBnB near Acadia. It’s a pretty long drive from Acadia to The Kankmangus Highway. We relocated before driving there.
I would skip the Kanc and drive north through the notch and head to through the National Forest. Stay over at the white mountain hotel or nearby motels. Then drive east towards Jackson and then back up past Mt Washington and the presidential range towards Berlin. Drive up my Washington and it’s seeing the whole foliage landscape for miles. You can go back to North Conway and head into Maine if you like or head south to Portsmouth and Boston to the south or Portland to the north. If south head back to Boston and head west on the pike and take in western mass and the Berkshires. Head through ny and the Hudson valley along the way to philly.
What a great college tour this could be too. Lol.
That’s a lot of driving. I recommend going from Albany to the Berkshires. All the towns along the Route 7 spine. A short drive from Albany and a gorgeous area with lots to do. You can use Great Barrington or Lenox as your base and take day trips to Vermont from there.
I really wouldn’t drive all the way to Acadia, as much as I love it there. I agree with brantly.
Also, Acadia to Philadelphia? Not 8 hours if you hit traffic in Boston, Prov, New Haven, NYC. Play with the arrival/departure feature on google maps.
Acadia to Philly…it’s going to be a long one day drive.
As much as I love the Presidentials during foliage season, I would not recommend this for this person who really wants to head further south on their journey.
The Kanc should be fine.
I do agree that the Rt 7 (in CT) does provide some gorgeous foliage driving, and you have to drive south somehow.
You might find some tips in this thread from a year ago.
I would strongly recommend not trying to drive from Acadia to Philly in one day. NJ to Acadia in one day is a lot (I have done it) and Boston to Philly is a lot (have done that also). Google map and GPS estimates just don’t work - there is always traffic along that route (no matter which route you take). You can easily spend 2-4 hours more than you plan making this drive. Maybe you could stop overnight in CT on the way down. The color will be nicer (since it is farther south than Maine/VT/NH and the leaves change later).
If you go to Acadia, I would strongly suggest you head south, and then west to get to Philly. If you stay on 95 too long, you will surely regret it.
Plus, there are some prettier more scenic roads inland.
Avoid traveling anytime near Columbus Day… higher prices, jammed hotels. I live in the West where Columbus Day is barely acknowledged… it was a curious surprise how big it is on the East Coast. And how negatively it affected our Boston-Maine foliage trip.
Interesting. It’s such a big deal here.
Looks like the OP’s travel dates for the New England part of the trip fall just ahead of the Columbus Day holiday which is Oct 14th this year.
It makes sense that Columbus day weekend is busy as the national holiday coincides with peak foliage season. Other than that, New Englanders don’t make a big deal about Columbus Day these days. Many of us feel it shouldn’t even be a recognized holiday. Perhaps I’m biased as I never had the day off in my career as it isn’t a day the financial markets are closed. 
I always saw it as the first school holiday and so soon after school started.
If you are in Vermont near Burlington the Shelburne Museum https://shelburnemuseum.org/ and Farms https://shelburnefarms.org/ and the Vermont Teddy Bear Factory https://www.lcmm.org/ also are fun to visit. The Lake Champlain Maritime museum is also interesting. https://www.lcmm.org/
But keep in mind that Burlington is about as far away from Acadia that you can get on your drive. It’s a pretty drive…but it’s long. And there are no east west highways…so you will be on scenic roads the whole way from Acadia to Burlington.
I think you would be better off heading towards the Bennington area of Vermont. Then figure out how to pick up Rt 7 from there and wind your way south. It’s very pretty.
It’s about a 7 hour drive from Acadia to Bennington, but you wouldn’t need to do it all in one day. You could leave Acadia and drive as far as either Portland ME or Portsmouth NH…and spend the night there. Continue to the Bennington area the next day.
Or you could do as you planned and take the Kanc across and drive to the N Conway area and stay there a night.
Then drive to Bretton Woods…worth it to go,that way just to see the Mt Washington Hotel vista…it’s gorgeous. Drive south through the notch to 93 and head south that way.
I lived in NH…when I first moved there, some one described the White Mountains during fall as looking like someone spilled Trix all over the mountains. The colors are gorgeous, and so many trees!
Yes, getting from Maine to Vermont takes forever, much longer than you would think from looking at the map. I haven’t made the trip in quite awhile just because it’s so hard.
Check the NFL schedule for your arrival in Philadelphia…just sayin, you don’t want to be trying to get into the city from the north if there’s an Eagles game