Yes, you can end up drawing more amps than your stator is producing. The 12V ACC (cigarette) plug is fused with a 10a fuse, so assume you get about 10 extra amps to play with for added electrical accessories. You will probably be fine with what you're planning but I've found that good quality lighting is much better than large, cheaply made huge LED lights. Don't forget if you're running heated grips/throttle too, (you mentioned) winch, those are pulling amps as well.
I do have many aftermarket electrical accessories on my Grizzly 700 but find it is very infrequent they are all running at the same time... you might find the same. For backup lighting, look into the Powermadd backup kit made for the Grizzly. It is really worth the price, which isn't too bad to begin with. But the light can be set to only come on when you put your Grizzly in reverse, just like automobile backup lights. Since I feel I'm burning more amps than my stator will produce while out plowing, I keep my Grizzly on a Battery Tender Jr once parked in the garage.
I do have many aftermarket electrical accessories on my Grizzly 700 but find it is very infrequent they are all running at the same time... you might find the same. For backup lighting, look into the Powermadd backup kit made for the Grizzly. It is really worth the price, which isn't too bad to begin with. But the light can be set to only come on when you put your Grizzly in reverse, just like automobile backup lights. Since I feel I'm burning more amps than my stator will produce while out plowing, I keep my Grizzly on a Battery Tender Jr once parked in the garage.