We plan to go late summer. We do not like fancy eating and hotels. Plan to be there for a week.
It depends where you want to stay at the Grand Canyon National Park, but there’s a great little gem of a hotel at the South Rim called the Red Feather Hotel. It’s not fancy, but it’s clean and reliable and even has a little Mexican restaurant called the Plaza Bonita. It’s very close to the Grand Canyon and also happens to be within walking distance to the National Geographic Visitor Center / Grand Canyon Visitor Center, which is a really fun attraction, especially if you happen to be going with kids as well as the Grand Canyon airport. It’s actually divided into two sections-a motel and a hotel so you have a couple of options.
The Canyon Café at Yavapai Lodge is a great place for a cheap meal at the South Rim. It’s more or less just a coffee shop/diner but the food is good and inexpensive. Mostly just American classics like burgers and fried chicken—definitely fits into the “not fancy” category.
For the North Rim, I would say the Kaibab Lodge is a good choice. Very cute little cabiny-looking place that’s definitely not fancy just cozy and clean. Kind of looks like a place where a cowboy would stay the night. They do have places to eat within the Lodge, but I would check out the Rough Rider Saloon. It looks like the place where the cowboys who stay at the Kaibab Lodge would go for a beer and some breakfast grub. Plus they let you sit on the porch and enjoy your drinks.
Mentioned in this answer:
Well, the area around the Grand Canyon isn't known for fanciness. Are you planning to actually be within that national park for an entire week? If you're not doing an expedition into the canyon, that might be a wee bit more time than you need.
I'd suggest basing yourself in Flagstaff. You'll have everything you need there nearly within walking distance of a hotel. There's the Hotel Monte Vista right in the middle of it all. If you want to stay further from the downtown area, there's Little America Hotel - Flagstaff. Plenty of others besides those. For restaurants, seriously ... just walk around downtown to find everything from burgers to sushi to Korean to pizza.