Well, i may not be the best person to answer but i am sure i am better than no one. plus, i was born in FWA, so i have sympathies there!
Q. What's the difference between planing in a cold frame and winter sowing in jugs?
A. size, disposibility, hassle. cold frames probably have greater heat retention due to size. they probably stay moister in high winds. cold frames are not as easy to move around. cold frame require a purchase, or handy project (or a lucky trash-pick/inheritance). wintersowing requires picking through your own & your neighbors recycling bin.
Q. What is the stratification period for seeds requiring the cold periods?
A. What is the germination time for the seed? time to harvest? the point is: it depends on the seeds.
Q. Do the seeds actually need freezing temperatures or just 40 degrees?
A. see above
Q. If you were going to stratify inside your home do you need to place in freezer or will fridge do?
A. i am much too lazy for that. that is why i winter sow!
I'm hooked on the wintersowing myself. I have a gazzion jugs out and I'm sure they have started to germinate. We have had several bright, sunny days of 60 - 70 degree weather.
I have a friend who wants to grow in a cold frame but wasn't able to put seeds out during the winter. We were trying to figure out how to get these seeds done yet this year. It seems that I read that strat seeds need at least 6 weeks of 40 degrees. I can't find that any where now. LoL Maybe it was just my imagination!
many of the seeds that do well for wintersowing can probably go out directly sown now like lettuce & greens, peas, in particular. a cold frame would be useful now for tomatoes & peppers. i just WS'd my tomatoes about 10 days ago. you can still WS or use a cold frame now. a cold frame will have be more closely watched since i hear you are hitting 70 some days. i gauge it by how hot my car is in the sun--it's the same solar concept.