If you can keep him with his contemporaries, the herd he already knows, he will be SO much better off than if you isolate him.
He will, however, need a lot of extra nutrition now that he has no mama to nurse. At two months, he might be OK to forgo the whole learn-to-nurse-from-a-bottle routine. I hope so, because bottle feeding is another behavioral can of worms. It can be circumvented by using an igloo cooler with an attached nipple. I have raised calves from 6 weeks with no bottle, but nutrition for a ruminating calf is not the same as for a foal. I simply fed very nutritional-density feed that also contributed to the health of the GI trace. For a calf, that was calf manna, sweet COB, alfalfa pellets, rice bran and beet pulp, with free choice very high quality orchardgrass and/or alfalfa hay. Hopefully you can have your vet help you with, or possibly provide you with a referral to, design a feed program that will work well.
Anyway, I would get the vet’s help with nutrition questions, and perhaps your little guy will need to be brought in twice a day, or overnight, to get his special foal chow. But for best results, I would have him out with the other mares and foals as much as possible.