I was hoping someone more seasoned might have answered your question, but I'll share what little I know. First, I do know that Maharishi is Orange Kardinal, to be shown as Orange Kardinal.

As for roses that may do well in cool summer areas, that's not my forte as we get 100+ heatwaves. But it seems your fall weather is probably more pertinent than your summers. You just need to survive whatever type of summer you have and gear up for the fall show season. That being said, it seems like Vetgeran's Honor, Dublin and Gemini are missing from your line up -- though perhaps you grow them and it does not prefer your micro-climate. My non-exhibiting sister grows spectacularly the climber Don Juan and the floribunda Black Jade in the bay area.

Now if your question is what blooms throughout the summer, for me it has been the English rose Molineux and Abraham Darby, the floribunda Lavaglut and trumpeter, the polyantha Marie Pavie and La Marne, and the HT Lagerfeld. It also looks like my new Black Baccara is going to be an all summer bloom machine.

Good luck.