Yes. It would be like breeding 2 het pied BPs. The normal offspring would be 66% het for pied, or in your case 66% het for snow.

This difference with your boa is that to be het for snow, it has to be het for two different recessive genes: albino and anerythrestic. So, while yes your boa is 66% het for snow, it is actually 66% het for anery and 66% het for albino. It may carry one or both or neither of these genes.

Hope this helps!