It is one of the hardest decisions for me - pulling up plants that are still managing but I must admit are on their way out, so that I can give pansies a good start. Many around here also have mums. Something I haven't normally done. We are still hot, but having some breaks. Finally having nights in the sixties and highs in the 80s.
As usual, my impatiens are the stars at this time of year. I wish they had bloomed more this year and assume it has been stress from heat. I looked at the buds being put on now, though, and I think they are getting their wind back a little. The regular ones - variety is Beacon - are happiest, with the New Guinea or "Sunpatien" ones really not keeping up, which is a surprise to me. Most folks really brag on the New Guinea but I haven't found them very robust, though grown in the same area. It occurs to me that I might enjoy trying a separate color of these at another area next year, for interest. I almost never grow the white - maybe that would be fun.
I grow them in pots, as it helps reduce the risk of disease and also I can easily move any that are struggling to a sheltered spot to give them a chance, and anything that dies can easily be whisked away. If I have "to many" ( not sure if that's actually possible? 
) The peony was very obviously too dry, so maybe it would be sensible to leave that area to the Periwinkle, as although a lot of that did die back in the drought, as soon as the rain came it quickly recovered. I've noticed that the rose that was getting choked by the rhododendron is also looking a lot happier now, so I'll see how that flowers next year before making any long-term decisions.