Come on over. We even have card pumps and ATM's in Idaho.
Visa and Mastercard covers most everything.
Not many responses so I'll offer a couple. Sept is great in the West. Late Sept should be very good for fall colors in the New England States. You are basically starting at the wrong end if the country, and it is a long way across.
Maybe head west, do the Great Lakes, Chicago, Mt Rushmore, etc. 5-6 days.
Hit some of the big calling card parks. Glacier, Yellowstone, Yosemite, Death Valley. These are big parks and take a day to visit plus a long day of travel, or more, in between. 10 days.
Vegas. ? days. What happens in Vegas stays in Vegas.
Grand Canyon, Monument Valley, 3 days.
Now you are in the middle of the country and have a week and a half to get to Toronto.
A long way to the Alamo, and Colorado is still out there.
Hit New Orleans then head north thru Dragon country to New England for the fall colors and festivals.
Hit the Maine coast if possible.
Ft Meyer in Virginia is splendid for US Military History. Tomb of the Unknown, Pentagon, Arlington Cemetary, Custis-Lee Mansion, the Old Guard and a cavalry unit. All in a close walking distance. Beautifully maintained.
While crossing the west Great Basin Nat Park and Canyon De Chelly are treats that many pass.
Hwy 93 is a good route north/south from ID to Vegas. Hwy 50 is good east/west thru UT and NV. I-90 in ID and MT is a good interstate as well as I-15 in MT. 15 is horrible thru Salt Lake City. The whole Utah population lives against 15 in the SLC area. 89 or 89a across south UT. These are a few good traveling roads.
So many choices. If you narrow it down a bit maybe some more help will come along.
I hope that helps.