it really depends on the varieties you are planting, what is best and what you can get away with is very individual characteristic of a particular plant/tree.
some things dont need stratification but will sprout after the cold strat, some wont sprout without it. some like to be stratified, but will be severely damaged by a hard freeze. the cold strat temps
should be more like 35-40 degrees, not frozen.
apparently this is the case with pecan and chestnuts, i have read. they need to be cold stratified, but not to fall below 28F or so. if you naturally cold stratify by planting outdoors in late fall --> mid winter the temperature under the ground doesnt get to be very cold, keeping a constant temperature far deep
underground, but also on the surface or just under, keeping it warmer through the grounds insulation.
but if you plant in pots, its a whole different thing. planting in pots gives huge fluctuations of temperature, the pot is exposed to sun and can get too warm, and is more affected by air temperatures, not having the grounds insulation....and can freeze solid. i often build up mulch and dirt into a mound, and put the pots into it, submerged into the mulch, to help keep a better more constant temperature.
here in northern california, the sun has been telling me its almost spring! and it can be tricky to try to cold stratify outside in pots, because we hardly never know when we will get our winter temps, if it will get suddenly warm for a bit like in jan, or feb --this often happens. then again suddenly it can just get super cold, again, though i think for this year we re done with the extreme here, which only gets down to the 20's.anyway this makes figuring out when and how to cold stratify, very tricky, and the fridge can be the best way because its reliable.
planting straight into the ground, direct sow, is the very best for many things, except then all your nuts gets swiped by hungry squirrels and what not!!! as happened to me this year. they didnt get all the nuts i direct sowed, so thats good, i spread out the nuts all along the edges of the
land here, and a least a few of the places havent been disturbed.
also most things that need stratification to break dormancy, need 2-3 month solid of cold temps. so thats the direct
answer to your question, theres not enough winter left to get a solid 3 months. however some things are not as dependent on the cold strat, and may start anyway...without very much time at cold temps.
most trees that need the cold strat are usually tough enough to handle all year round without getting funky. so if you plant now and they dont come up cause they didnt get stratified, theres a good chance they will come up next spring, after all year and then next winter.