Thanks so much, Margaret. I appreciate your response.
I was so (selfishly) focused on the issue of elevation and short growing season, that I neglected to comment on your seedlings. I love the colors on 'Big City Eye' x unknown, and especially 'Black Eye' x unknown. I'm guessing that those two named cultivars are well suited to your conditions, and thus those seedlings are also? (I am thinking here about something Richard Norris wrote in an essay on northern hybridizing... his point being that you should select as parents those cultivars that perform well under your conditions (not necessarily under their hybridizers' conditions).)
You certainly have a hybridizing challenge there, but how thrilling and rewarding it must be to see those seedlings bloom under such adverse conditions.