I wouldn't bother with the .223 round for deer in Maine if there was any other choice. When in high school and college, I had a .30-06, but never shot a deer with it, so I sold it and bought a .22-250. I then shot three deer in as many years. Guess the deer weren't intimidated by it, but they were wrong. However a couple of experiences with the smaller caliber convinced me to get another .30-06, but to keep the .22-250 for varminting.
Years ago, I had bad experiences with the .22-250, using 55 grain solid-based Nosler bullets. It killed fine when I could take the time to place the bullet exactly where I wanted it and where there wasn't a twig in the way, but I missed at least two huge deer because the bullet couldn't get through a few tiny branches without being deflected. Yes, it did kill a few deer in open areas, but if you don't have to rely on such a small bullet, you're better off not doing so. The first shot is the so critical when it comes to hunting; relying on second - fifth shots is not often going to result in a clean kill.
After those two instances I got another .30-06 and shot a lot of deer with few misses due to brush, but I'm also careful about placing shots between trees/limbs. Scopes allow better placement, especially in darker woods.
I let my brother-in-law borrow the .22-250 one day, but cautioned him to shoot only at standing deer and through the lungs. Well, two hours later, five deer ran by him in a field and he shot one in the hindquarter as it was going away. The wound ruined the hindquarer and we had to track the deer a mile before another hunter shot it and took the bro's first deer away. It was an excruciating lesson for him. I wasn't too darned happy either.
My .270 has been be okay in the woods, but probably not as good as the .'06 with heavier bullets. I use it mainly for fields and woods roads.
Picher