First off don't take OR 242.
OK on a bike, car or small MH. It has a length limit of 35 (?) feet. Has cameras to spy on violators. Every now an then a Super Trucker tries it and gets stuck. Narrow, rough, windy and closed in winter. It is beautful drive and has an observation point at top up a short walk. Can see, on a clear day 7 (?) of the Cascade peaks. If you got a car or such consider making a day trip up there either from Sisters or the Blue River area.
US 20 out of Ontatio is a rather dry and dusty route. US 26 is a lot more scenic. OR 7 out of Baker to US 26 is a nice drive.
If you take 26 in Prineville pick up OR126 into Sisters then you can connect with 20. You can follow 20 all way to coast. The section over the Cascades is rather windy but totally doable.