Since the Wedding is 23 miles outside of Portland, you'll probably want to stay in the city so you'll have more to do when you're here.
Here are some hotels to check out:
Hip & Swanky
Scary Cheap (but across from jupiter)
Front and Center Nice (rose festival parade congestion)
WaterFront and Center Nice (fleet week and carnival congestion)
Get-in-Get-out-Quick! + Free breakfast
Would you like to see the registry? or maybe the location?