If what is viable?
It's clearly illegal if you run it from Canada (no substance in the other country) and the company doesn't pay Canadian tax.
You need to speak to a Canadian tax lawyer about this if you don't believe me.
If you understand it's illegal and you want to take the risk, maybe a US LLC will work, maybe it won't. I could imagine that there︀ is more information sharing going on between the US and Canada than between the US︁ and, say, France, but I don't know. Maybe not.
In any case, any assets held︂ by a US LLC at the time of your death will be subject to US︃ estate tax, unless a treaty says otherwise.
There is an estate tax treaty with Canada,︄ which means inheritance tax would be paid in Canada and that there would be no︅ or less estate tax in the US.
But then how do your relatives get the︆ paperwork from Canada that tax has been paid after inheriting a company that should have︇ paid taxes in Canada, but didn't?
Maybe they won't ask questions since you'll be dead︈ at that point, but maybe they will? That's a lot of ifs...
But maybe that︉ risk is acceptable to you, then that's fair. I'm just a fan of people making︊ informed decisions.