In case anyone else is interested, here's my new workflow for setting and maintaining a season's worth of rates/min nights. The Rate Calendar is a critical piece to the workflow.
a) I do one large session where I establish Nov-Apr rates, and put them in a clearly marked spreadsheet that I'll save forever outside of OR
b) import the spreadsheet as spot rates, and then 'push' the rates to VRBO or elsewhere
c) (this is new) Whenever I feel the need to revisit rates, I'll now pull up whatever information I feel is helpful, such as comparing with my competition by doing live searches, along with looking at previous year rates for similar days, and I'll have my original spreadsheet open. Next I open the Rate Calendar and change two ranges for any week that I care about - Sun-Thur and then Fri/Sat. This goes quickly, and lets me tweak each 7 day period with a minimum of effort. Any unique dates like valentines day weekend or of course Christmas can get unique rates per day just by either picking a 1-day range or using the toggle feature.
d) After my updates are all made, I need to 'push' the spot rates to VRBO.
e) I now will 'export' the spot rates to another spreadsheet, so that over time I'll have a record of my original rate settings for the season, and then each time I did any other changes. I like that because it gives me the ability in the future to put all the rates for a given property into a spreadsheet and do some simple formulas to highlight dates where changes happened.
This might be more complicated that necessary, but I really like to have the records of rates I've set along with changes... maybe with time I'll get smarter about predicting how to set rates and realize which dates historically need to be discounted.