Hello Kevin,
The submerged plants should be OK, however the WH is tropical and will freeze. You could put it in a container with pond water and keep it in a basement, garage, etc... somewhere that does not freeze. Otherwise just plan on buying more next season. Lord knows it regenerates quickly.
Hope this helps. Dianne

Last winter all my anacharis died and made a mess in the bottom of the pond to clean up in the spring. This year I bought hornwort and I'm hoping it's hardier than the anacharis was.

Water hyacinth is very tender and will die with the first frost. It's better to take it all out at that point. It hates cold water and will start to yellow even if there's no frost to kill it right away. I'm taking mine out as soon as it starts to look bad.

Instead of tossing it - for those ponder's in the Chicago area with Water Hyacinth... Brookfield Zoo is always looking for some at the end of the season to feed some of their monkeys, etc... Just thought I'd let you know.

Maybe some other zoo's or animal sanctuary's in other states would like some too!

Tina