A year+ ago, I tried to make lemon wine from basically lemonade, I am
certain it was too acidic, and fermentation refused to start. I don't
think preservatives were a problem. The groups consensus was something
like lemon juice--or even lemon aid--would have to be cut by something
else.

I thought about this again after playing around with lemongrass for
cooking. Could I get a refreshing wine from something like this?

(for ~1 gallon)

1/2 gallon juice from Welch's white grape juice concentrate
1/2 gallon lemonade from concentrate w/o preservatives
3 sprigs of lemongrass, finely cut (food processor)
3 tbsp fresh ginger, finely cut (food processor)

I wonder if cutting a lemonade in half would reduce the acid enough to make
this viable. A somewhat related question would be what I can do to cut the
acidity of lemons in general.

Alternate ingredients I assume would be leaves: lemon leaves or lemongrass
leaves; or perhaps other things with a lemon flavor; or a pile of lemon
zest.