5 is the high side, not the low side, according to the sentencing guidelines (which directly capture the fact that it's North Korea he helped; the sentencing guidelines for 50 USC 1705 practically read as if they were written specifically for North Korea).
Not to nitpick, but it's not like the sentencing guidelines are binding. The judge can still choose to hand down a sentence outside of what the sentencing guidelines prescribe. Case and point, Paul Manafort and his "otherwise blameless life".
I'm just going to say that the sentencing guidelines capture 50 USC 1705 directly and are written in such a way as to suggest that North Korea is exactly what they were thinking of.