I often use a bivy alone in drier locations with shorter wet periods. My opinion is that roadside Alaska has conditions that need a roomy tent (for one person) due to rain and bugs. The OP is expecting to live in the tent, not just sleep there while hiking. A different use with a different solution than a climber or a thru-hiker would choose.

It is good to know that there are no bug problems while it snows on a tarp/bivy combo high in the mountains.