How can I help the birds in the snow and extreme cold that’s in Mississippi right now?

I filled my three feeders to the brim yesterday. I don’t have much leftover. I just want to help however I can. I live with an acre of woods, so lots of birds and other animals. Any ideas for them are appreciated too, although this isn’t the subreddit for that, and I’m mainly asking what I can do for the birds. I have power and water.

I’ve heard putting birdseed on the ground is good, but I’m not sure if I should do that or save it for my feeders. What about water? Is there anything I can use besides birdseed if I run out? Thanks.