j4co
Pulling my weight
I assume the level how deep the soil freezes in winter time.I would run
I can not comment on the frost line issue cause down here, WTF is a frost line lol.
Here it is assumed if you go deeper than 60 cm it will not freeze. But we tend to get hotter climate and days with negative temperature (celcius area where 0 is freezing point ) get less frequent in winter time.