Crabs cover a wide range from pea size to small apples. Do you want to feed deer or birds? Seedling crabapples are available from many sources. You never really know what you'll get from seedlings so planting more is better. For smaller plantings, grafted trees are a better bet. Saint Lawrence Nursery in northern NY has a good selection of late ripening or late hanging crabs. For deer and birds, their varieties All Winter Hangover, Violi's Hanging Crab, and Winter Wildlife Crab would be good choices plus other crabs that are more for birds than deer.
X-2 with Chickenlittle. I have those crab varieties planted at my camp and they are kicking butt !! Got them from St. Lawrence Nursery too. Kerr apple/crab cross is supposed to be a late hanging apple/crab as well. Good to eat AND draw deer.
As for disease-resistant apples that hang on late - Goldrush, Enterprise, Winecrisp, Sundance. Dolgo crab ripens in late August and goes into September. Not a late crab, but a good crab to have for pollination and early-season deer attraction.