I've landed on heading up 89 by Tahoe to Lassen and then up to Crater Lake.
I'm trying to avoid 100 degree heat and hoping the road is clear of snow on the same day. Lassen wasn't clear in 2017 until July 26.
For reference, these are links to the road conditions in:
Lassen:
https://www.nps.gov/lavo/planyourvisit/winter-road-closures-and-spring-clearing-update.htm
Crater Lake:
https://www.nps.gov/crla/planyourvisit/conditions.htm
Yosemite:
https://www.nps.gov/yose/blogs/fireinfo.htm
For miles per day, I've compared what we did last year and in 2016 to what I have planned for this week. It's only one week, but it's also on an unfamiliar bike, so I'm trying to be a bit conservative.
California 2019 plan:
290, 342, 285, 283, 330, 346, 223, 178
Colorado/Wyoming 2018:
383, 477, 312, 362, 275, 130 (Canyonlands), 437, 358, 477, 364, 325, 332, 393, 219, 400
Nova Scotia 2016:
648, 127 (Niagara Falls), 249, 230, 241, 287, 243, 39 (Bar Harbor), 465, 381, 440, 362, 366, 530, 375, 347
We had a good balance of riding and sightseeing on these other trips and we both handled these miles well. We have it timed out to get through Yosemite by around 9:00 on a Monday to avoid some of the traffic. We did that with Yellowstone and with a rain prediction that didn't come to pass, we had the road to ourselves a lot of the time.