We would recommend staying in Pullman for your convenience, though hotels in Moscow, Idaho are also within 15 minutes of the Ronngren Farmhouse. There will be plenty of space for parking at the house, but if you can carpool that will help out with space! :)
Hotel
Courtyard by Marriott Pullman
1295 Northeast North Fairway Road Pullman, WA 99163 (509) 332-1500
Hotel
Residence Inn by Marriott Pullman
1255 Northeast North Fairway Road Pullman, WA 99163 (509) 332-4400
Hotel
Holiday Inn Express & Suites Pullman, an IHG Hotel
1190 Southeast Bishop Boulevard Pullman, WA 99163 (509) 334-4437
Hotel
The Historic Davenport, Autograph Collection
10 South Post Street Spokane, WA 99201 (509) 455-8888
Flight
Seattle-Tacoma International Airport
17801 International Boulevard Seattle, WA 98158 (206) 787-5388
Rental cars from several companies are easily accessible at SeaTac.
Flight
Spokane International Airport
9000 West Airport Drive Spokane, WA 99224 (509) 455-6455
Rental cars from several companies are easily accessible at Spokane International Airport.