We have stayed in a lot of Airbnbs and VRBOs in the past few years of traveling, some for as long as 1-6 months. We have never seen any evidence of any type of video surveillance and have had very good experiences with most of them. That is either an urban myth or just the case of a small % of units. I'd never even heard of it! So, I wouldn't let that stop you. Read the reviews and choose a place you like.

We stayed way up on the north side of town in a hotel, so I wouldn't necessarily recommend that, though were able to ride and take the metro into downtown. I don't remember there being many hills -- nothing like Seattle! Needing a pet-friendly place limited our options, and we were only in Portland for 3-4 nights so not worth messing with VRBO/Airbnb IMO. Given how the weather may be for your trip, I'm not sure I'd bother taking the bikes, but then, I'm a cold- and rainy-weather-cycling wimp!