Not an upgrade but some remarkable DeltaOne pricing:

I am planning a trip to Spain from 12/27 - 1/08. No flexibility because I’m taking my granddaughter who has to be back to her college by 1/10. I have been randomly checking prices, planning to fly PS. On one of those random checks last week I snagged DeltaOne tickets for BOS-MAD and return BCN-BOS for $2157 each. The D1 price was lower than PS.