Im waiting till Oct 1 to plant my stuff in south georgia. The peas will last until first frost and give you good hunting the week after there planted. The oats will take a while to thicken but then will be good to go for the gun opener.
Absolutely NOT too late to plant ICP's. However, the deer here LOVE ICP's and will not get off of them until they are GONE to the dirt line. So, if you don't have a way to prevent the ICP's untimely demise, be prepared to shoot fast as they will not last too long I fear.
At least in reference to the Oats, Just planted 1/2 of ours in SC last weekend, and gonna try to plant rest this weekend. B/c of rain and drought issues in our part of country, we usually don't try to plant fall plots till after mid september.