If you're sure which ones you do and don't want to keep there's no reason not to try to sell the extras now as chicks.
If they don't sell as new chicks you can re-list them once they're off heat as started birds and if they don't sell that way you can re-list them later as POL pullets. Raise...
When I integrated the Welp chicks last fall it was several weeks before they'd come out of the coop into the run.
I wasn't there to see it myself, but my 16yo reported that they made their first trip outside under Ludwig's supervision -- their big brother babysitter. :D
I always wear wool socks.
I have a job where I spend 8 hours on my feet walking on concrete and my super-thick, Omniwool, padded hiking socks are the salvation of my feet. :D
I even wear them in my boots in the summer because my feet sweat so badly that cotton socks get soggy and disgusting...
:D
As a Yankee transplanted to the south:
Our cars don't have snow tires.
We don't own heavy winter coats, gloves, and boots. My muck boots have tread so I can walk on snow, but no insulation (they're hot enough already when I'm working in the coop on a 95F degree day in July).
Our heat pump...
Indeed.
My chickens are locked up for the recommended 30 days in re: Avian Flu and they're getting a little rambunctious even with almost 12 square feet per bird available.
That's almost 9 square feet less the space taken up by the feeder and waterer so it should be OK for a few weeks of growth and see-don't-touch integration.
After the initial adjustment, if you can rig a way that the littles can get in and out but the adults can't -- maybe using a hook and eye...