Work suddenly got so busy, I could not stand to open a computer after 14 or more hours of work.
I got it! Let Copernicus be my guide, I am no PCT mountaineer! I went on early May trips in 2017,2018, 2021 and 2022 and will use those trips as guides to what I see on Copernicus.
SSSDave, I have done all of that car camping in most of the areas you recommended when my kids were young. However, once I learned to use crampons, camp on the snow and, in general, about safety in snowy camping and hiking, I felt so liberated, I never wanted to go back down again

WD, my dogs have never felt the altitude as much as I do. However, my Jasmine Rose is the first dog I have had who seems to feel it. We seem to acclimate at the same speed so it works well for us.
For spring trips, I prefer to pack in and base camp. For one, I have a really heavy pack with all of the cold weather gear. The other is, I like to stay reasonably close to a road in case bad weather suddenly kicks up.