Mandeville, the winter is great for planning the next season (there is a thread elsewhere with various peoples 'outlines' of their objectives for next season you could look at elsewhere on this forum).
Your gifted late nuc was perhaps a shot to nothing. Hopefully they will pull through winter and give you a platform to expand both colonies and experience from next season, but I don't think they should be your only strategy element.
What are your plans if they dont pull through, buy a nuc, bait hives, swarm donation?
What if they get through but are weak, how will you build / supplement them?
If they do go like a rocket what is your intention then? split them, take a late small honey yield?
Now is the time to be mapping out options and put in place the supports / equipment, not forgetting the knowledge you'll need.
The good, bad and ugly on here will happily support, build on, tune (or rip apart) your ideas of course, but better those strengths/weaknesses are discussed and resolved here in cyber space than played out in real life at your apiary (to the cost of your enjoyment, bees welfare and pocket)
Your best chance of constructive support on here is to think through and research your proposals, in my experience the rottweillers are less likely to bite yer arse if they see some self help and effort rather than just taking their 'wisdom'
Plan A looks a bit flaky on current evidence, what you going to do then?