Feeding during "Indian Summer"

I am a very new ponder here in Zone 5 Ohio. Put in one of those 90-gal.
preformed kits in the spring, and we love it!

Here's my question. I really didn't feed our two 4-5" goldfish (one
comet and one something else -- all orange!) all summer. Now we have at
least nine, maybe more, babies. The weather had gotten quite cool and
the fish all were pretty inactive. I had read that you shouldn't feed
fish when they start their metabolic slowdown for the winter.

Now we're in a weeklong stretch of 60-70 degree days and 50s at night.
The fish seem quite active again. I worry about them (especially the
babies) having developed enough body fat for the winter.

Is it OK to feed them during the warmer temps or should I just let them
chow down on the anacharis?

Thanks!
Frances