Help with wild doves at my house?

I would say clean up your balcony and regain the use of it. The egg is very probably dead, being cold and all, and in any case the wild doves will lay another batch of eggs when they find themselves needing to, in order to have a chance at reproducing this year. SO, even if there is still a chance that the egg might still be alive, you will be doing the doves a favor by removing it so they can start over again for the season, and maybe raise 2 or even 3 children!!