All good roads. 58 has a 6 mile 6% uphill going east but the downgrade isn't much. Collier State Park for a day trip to Crater Lake.
https://oregonstateparks.org/index.cfm?do=parkPage.dsp_parkPage&parkId=165 And go to the logging museum across the street if your interested in old iron.
From Newport you can also take US20 east to I-5. It is also a fine road. Four small pulls but they are short and under 900' in elevation.
In theroy you can take your MH to Crater Lake but I wouldn't advise it. There is several buses that do tours around the lake and they make several stops, or you can drive your own.