Simplify3D - paid but no access ????

[Ward]

Then it's definitely trouble sleeping.... trust me.
But assuming they won't reply is pretty much a defeatest attitude. At the very least send them a nice inquiry, at the very least it will place you higher in their CS queue after the holiday.
If they're customer support is decent enough, they'll at least fire back a "We'll look into it" reply.

Assuming they won't reply during a holiday is not "defeatist"...it's common sense.