Wines I'm Making: Harvest 2020--First Test of Grape Ripeness

I took a sample of the Sangiovese grapes today, Tuesday, September 15, 2020, the first check I've done on the ripeness of the grapes this season. They are at 19 brix. I usually like to harvest the grapes for the rosé we make every year at a somewhat higher reading than that (ideally 22 brix) and typically we harvest a little later than this, but I'm worried that the very hot weather we had at the beginning of September (up to 111 degrees!) may have accelerated ripening. I can't find my pH meter, so wasn't able to test the pH level.

Many of the seeds are completely brown, suggesting the berries are ripe even if the sugar is a little low. Do I wait or do I pick soon and chaptalize, if necessary? A little research is in order. I'll have to go back and look at what I've done in the past. It's hard to remember the details from year to year. I need to refresh my memory.