If you only need to do it a few weeks a year I think you'll be fine doing 95%
But if you are down to 10% when it's 0F out, routinely, sooner or later you're gonna run into trouble (snow or traffic).
I'm kind of surprised you can't do the round trip in cold weather with enough Margin.
What model SR? Surely a LR would do this in a breeze even in extreme cold.
Make sure Sentry if Off and Summon Standby is off while it's parked all day.
Don't waste range on preconditioning when not plugged in.
Model 3 heats cabin extremely fast, it's just not needed and will only reduce your range.
While plugged in, precondition all you want, but it is wasteful on energy.
If you need range, charge based on departure time to 90% (or even higher) you should be fine.
This is more costly on energy too. Ideally charge the when arriving home on a warm battery.
But if you need the range use the departure time charging.
I think you get warnings below 20%. And I think 20% is a good warning mark for cold weather driving.
In case you get stuck in snow or traffic. 10% is not enough of a SAFETY Margin in cold weather.
I'm talking about safety for your wife, not the battery.