The best way, of course, is not to leave it to the bees, but do it yourself by putting the pollen of one rose on the center of another bloom, and covering it up with the toe cut out of some old ruined panty hose. This will keep bees and bugs out and insure the cross you made is the only one made. This is why China Hybrids are only spring bloomers unless crossed again. I will plant Mme. Isaac's seeds because Cramoisie was probably the pollen parent there, so chances are I'll get mostly everblooming seedlings.
Some roses make better seed parents than others.
It seems to me that Hybrid Perpetuals and Bourbons are good potential seed bearers. Then remove to 70 degree temperature for 6 weeks, and then put them back into the crisper at 40 degrees to 42 degrees. Our very early spring temperatures should be about right for them. Few will germinate and those will be very erratic about it.