The plants you are concerned about do indeed need moisture. Keeping them moist as they head into winter is important. Share your dish water and bath water with them! Set up a rain barrel for next year. Plants seem to like nature's water best. I cut back the hostas and ferns in Autumn usually as it helps keep slugs away. The dead foliage of hellebores gets cleared away in early spring to make way for the new blooms. Heucheras also need tidying up to allow for new growth. I do that in spring also.

Oddly enough it is very soggy here in Ontario. A nursery sent us this email message today:
WET WET WET
"It is not uncommon at this time of year to send a little reminder to all of you about remembering to water your evergreens and other plants so that they are adequately prepared for winter. There is little question that this reminder won't likely be required this year, and we are seriously considering ark building as an alternative to landscaping. While it is not uncommon to find this kind of weather in late October and early November, all of the rain that preceded it in September has really made it impossible to complete our usual fall schedule of work here - although we continue to try."...

I'm not sure where you are in IL. In northern IL we had a 75 year drought in 2005. Because I'm in a very rural area with a shallow well, I avoid watering as much as possible. The hosta all survived as did the heuchera. Lost some ferns and a hydrangea. I mulched heavily, watered maybe twice in the hottest months. Many plants including roses did not bloom well but they did ok and came back in 2006. If possible water a couple times to help them thru the winter. As gardenbug suggested, use grey water. A pain in the patoot, but it works. Good luck!

After that extreme drought experience, I decided to plant a lot more drought tolerant varieties. I don't intend to be hostage to watering schedule.

We had a very dry summer and fall in 2003 or 2004, can't remember now. Everything came back fine the following spring although they didn't look like they would. I think having too much rain is worse. You should mulch earlier next time to conserve moisture and cool the soil. I only watered in the evening to avoid as much evaporation as I could. The things that suffered the most were plants I transplanted. So I'd avoid doing any of that until you get more rain.

Some of the Hellebores can also be drought tolerant - orientalis and foetidus I can vouch for. And some of the older Hostas are pretty tough as well. The leaves might be very small but they tend to come back once the drought has broken.

One greywater source that is relatively easy to 'capture' is the rinse water from your washing machine. If you use a biodegradable soap for laundry then even the washing water can be used around dry trees and shrubs.

Unless you have a small machine, you have at least ten to fifteen gallons going down the gurgler every time your rinse cycle runs. If you set up three or four 4 gallon buckets and a bailer by your laundry tub you can capture enough water to make it safe to leave the plug in your sink and walk away to empty the buckets where needed without coming back to a laundry room flood. (Do a test run first!!!)

After a nasty run of drought here I rethought the garden so that the tender treasures were much nearer to the laundry door and the tougher ones went into the further reaches. Saves the steps and stretched arms.

Have some of our rain - it won't stop. Rain, rain, rain - I feel like I'm living in some kind of sci-fi distopia like "Blade Runner". The rainiest year I can remember here, it's terrible. The last few years have been too dry. Why can't they just average it out over the years?

yaya_820, where are you in Illinois with no rain? I'm in northern Illinois and we are so soggy I expect lots of things to die. Illinois IS a very long state. Is southern IL dry?