I sometimes bring an extra game bags set per animal but not always. It's easy enough to river wash TAG Bags clean and dry them over willows. Takes <30 min to dry out while the meat gets handled, trimmed, flipped, aired out or whatever.
I try to avoid contractor bag or plastic bag usage unless ambient temps stay above 60F, and even then meat stays in plastic only as long as beneficial. If "submersing" meat in bags, 1-2 hours under water is about it for effectiveness.
As meat cools the first 48 hours the meat temperature is falling as gravity drains vessels, convection and radiation heat loss results in sweating and evaporation, many fluid dynamics to respect with wild meat care. If you place meat inside a plastic bag, sweating will occur and humidity inside the bag (fluid trap) is almost unavoidable. This creates an environment absolutely opposite our meat care goals.
It's tempting to tightly tarp or protect meat bags inside a plastic bag "temporarily" on the drift, but i've been able to demonstrate that it's okay for meat to get wet on-the-go as long as airflow and ventilation is maintained and meat gets cared for effectively and dried in a shady spot once in camp.