Update: I haven't had a chance to try Avalanche gulch again, due to bad weather every weekend since my first attempt. It's snowed pretty much every weekend since, with good weather during the week. Stormy weather this time of year creates conditions that are too icy on Red banks at dawn, since it gets slushy during the day and freezing at night. In fact, about three weeks ago, several climbers fell on Red Banks, killing one climber and critically injuring a few others. They couldn't get a grip with their crampons.
And now the snow on Red Banks will be gone before I have a chance to go again. And that's because I have Covid and need to regain my strength.
So the plan now is to hike 14,252' White Mountain Peak east of the Sierra. It's just a hike, but not an easy one. It's a 15 mile hike with 3500 feet of elevation gain. It will be a good test of how my body responds to the altitude. I haven't been above 14,000' since the '80s.
After White Mountain, I'll go back to Shasta and use a different route than Avalanche Gulch. Probably Clear Creek, since it's the easiest.