Welcome Aboard to Bonsai Nut! It’s great to see another ‘Nut join the Bonsai Forest.
Please move the satsuki inside.
Yes, satsuki do best outside, but can’t handle freezing temperatures while potted , especially young trees, when the rootball freezes solid.
Also the winds in your area will dissicate the tree.
Together that spells sure death.
You are a big hamstrung as far as options for raising satsuki. Keeping it inside for the duration is the main option.
In this case one would want an overhead led light source on a timer and mist occasionally, ensuring the media is moist, not wet.
If there is an indoor garage, preferably with a window, that doesn’t freeze a lot would be a really good option
In this case one would want an overhead led light source on a timer, an heat mat on a thermostat and mist occasionally, ensuring the media is moist, not wet.
Here’s a garage set up for cuttings. There is a heat mat under the seedlings. Thermostat is an Inkbird with external probe

An indoor set up would involve lights and timer. Set light timer for 12 hours. When daylight outside grows, adjust accordingly.
Good Luck!
DSD sends