It's a bit late to be dividing now but you might just be able to pull it off. Generally the recommendation for dividing these types of grasses is at the beginning of their growing season or late spring, just as new growth emerges. Once the temps start to cool in fall or when miscanthus normally starts to produce seedheads in your area, the roots stop growing for the season and it makes it tricker to divided or even to establish new plantings. But you have about another month or so to accomplish this before the plant starts shutting down.

If it were mine, I'd wait until spring.........even in my very mild climate :-)

Ok, yea the more I thought about it. I'm going to just plant it and in the spring decide if I want to divide it or buy another one for the other area I want it.

I divided my 5 plants in late feburary..I now have 20-25 plants lol..They all are doing good , except 3 or 4..They arent dead just not thriving.I dont understand it because the ones less than 10 feet away from them are doing awesome.Heres a picture of one I took today

Generally, first year divisions can produce mixed results. You may not have gotten as much of a root system with some clumps as compared to others and that can slow establishment. I'd wait to see how they perform next year before I'd make any decisions about whether they should stay or go. Also growing conditions can vary widely from one area to another, even ones quite close by. That can account for differences in performance as well. The one in the photo looks like it's getting quite a lot of shade? If so, that will certainly slow down establishment.

Thanks for the info gardengal

The one in the picture gets alot of morning shade but gets alot of mid day and evening sun(over 7 hours in the middle of summer)..Thats a picture of a healthy one but I have about 6 others in another spot that are the prettiest/healthiest of my collection.They are in very rich soil ive been mulching the last 5-6 yrs.Whats crazy is my collection started just 2 yrs ago.My mom had 2 of them in a very shady spot and they was looking sluggish.I dug them up and made 5 from the 2 plants at my house.In one year they flourished!! The next winter of 2016(late feb) I made 20 plants from those 5 ..That should give you an idea how big they got in just one year.I did plant them in very good soil with ALOT of sunlight.Matter of fact the 6 that are my prettiest/healthiest are in the same spots I started 2 yrs ago..They are HUGE right now .I can probaly make another 20 plants this upcoming feburary again but think I am gonna take a yr off from dividing.I divided daylilies,iris and zebra grass last feburary.Probaly over 100 plant total. so will probaly take this feburary off and let everything get established another yr.