Heartbroken Seek advice introducing new chickens to remaining 2 hens

Hi all,
this is my first post. I decided to join because it has been so helpful to read the posts as we got our first chicks in April...a Dominique, an Austrolorp, a speckled Sussex, and a silver laced wyandotte. As some of you said , did I ever think I could love a chicken? Well, I hoped so but didn't realize how much!
I am posting here because we just lost our second-the Dominique in July in the afternoon while we were nearby...just gone. no sign or sound of struggle but the Sussex was freaked out and the others ok. We were devastated.
Then last Monday, a fox (we feel sure) took the austrolorp. I am heartbroken because she was like a puppy. Always underfoot, cooing away at me. When I was planting bulbs last week she kept jumping in the hole and looking up at me. I would lift her out of the way and in she'd hop again. So I am really having a hard time accepting she is gone. She had just started laying and was producing an egg every day.
Also trying to figure what to do from here. We live near Saratoga, NY which has cold winters. As we get colder, we have only the Sussex and the Wyandotte. they don't like each other all that much-the austrolorp was the queen and kept order and kept track of everyone. now the Wyandotte is pecking the Sussex and they don't stay together as much as they should. And the Sussex seems a bit lost. I should add that they were free ranging before Gertrude died (the austrolorp) and we are keeping them in their pen a bit more now which they do not like. the Wyandotte was laying but hasn't laid since Gertrude died and the Sussex hasn't started to lay yet (late? Lower light of fall? Trauma from losing part of her flock?)
With winter coming it seems like a bad time to brood new chicks or introduce an older pullet/chicken. we have a friend with a rooster he says is amazingly gentle-protects the hens and makes sure they are ok. he has offered him to us but I have resisted having a rooster.
Any thoughts? is it better/okay for the 2 girls we have now to remain a duo and hope for the best? if we did, at some int, take the rooster, how best to introduce him?
Or what about borrowing the rooster and letting the girls produce chicks (in the spring I should think)?

I know I am too sad to do anything right now but we would appreciate any advice others may have. All kinds of good thoughts to you others who have lost hens....you're right, CAChickenNewbie,-it is only a slight condolence to know what good, happy lives they had...but some.
Thanks much.