If there were 4 more Tesla HPC type chargers between Seattle and San Francisco, the trip would be an easy 2 day drive. Add Tesla HPC type chargers near Redding CA, Eugene OR, Portland OR, and Olympia Wa.
Then the possible drive would be:
Leave Menlo Park at 8AM.
Get to Davis CA at 10AM, charge for 1.5 hrs. over breakfast, leave at 11:30AM.
Get to Redding at 2PM, charge for 2.5 hrs. over lunch, leave at 4:30PM.
Get to Medford at 7:30PM, spend the night and charge on a slow mobile charger.
Next day, leave Medford at 7AM.
Arrive in Eugene at about 10AM charge for 3 hrs. eat brunch, leave at 1PM.
Arrive in Portland at 2:30PM, charge for 1.5 hrs. leave at 4PM
Arrive Olympia at 6PM, eat dinner and charge for 1.5 hrs.
Get to the Seattle area at about 9PM
If there were just 12 or so high speed chargers, one every 65 miles, then the trip wouldn’t even need any planning.