Ok, I tried frogbit in my pond this year and was pleased with its growth
(it's a freaking unstoppable juggernaut really) though I am unsure of what
to do now that winter is here. Do I remove all of it and put some aside in
my stock tank to winter over like I do with some of the other pond plants,
or will it be okay to leave in the pond...

Now that I think about it, I'm assuming its an annual and should be removed,
no?