I raised 6 of my own, not all at once, and that was more than enough for me (busy/hectic wise), but having 6 or more (all at once) kicking, crying, fussing, and screaming, I would definitely employ the help of immediate family to aid me with the transition.
At the top of my list for in-home care and help would have been my mom, one or two of my sisters, and a close lifelong friend of mine. Both day and nightshifts would be reality for a while, at least until I had time to rest and recuperate from the pregnancy, and then I would gradually cutback on outside help and support as I settled into a schedule.
I wouldn't deviate so much as a single percent as to what I did and how I did things when raising my gang. Homemade baby food and formula would be at the top of my list, as would cloth diapers, babies would be doubled-up two to a crib, and once a week I would enlist the help of a couple of experienced babysitters to come into the home and allow me time to escape for a while so I could maintain my sanity.
Another thing I would do, I'd invest in another washing machine and electric tumble dryer to handle the laundry load, and unlike how fussy I was when my kids were little, I would more than likely have to learn how to stress less about the little things, and I suspect meals would become a whole lot simpler, at least for the first little while they would.
Have to say as fun and frightening as it is to think about, I am so grateful it didn't happen to me IRL, though I know I would have survived.