Meh, you can drive winters in the summer. You just have to accept they'll wear out faster when it's hot. They work fine in the Summer traction wise, your typical all season is not much more than a performance winter tire with a more general purpose tire compound (wider temperature range, worse performance when it's cold but can take the heat). So no rush if you don't want to buy summers this year.
20k miles on 3x summer tires isn't much value there most likely. My summer tires will be lucky to see 20k miles before the recycling heap.
2015 STi: Still Stock
04 STi, 04 WRX: SOLD