August Blacktail

[OXN939]

Planning a drop in DIY trip to Kodiak this year, which, due to scheduling constraints, will have to be mid August. Climatology shows an average 40-60 degrees that time of year. Anyone successfully dealt with keeping venison good in that environment or have tips for how to do so? If all goes well and we get deer down early on, I'll definitely pay for a "meat flight" to take it out of the backcountry, but even with that preservation is a concern. So, as of now, I'm looking at either sinking zip tied contractor bags in an alpine lake or bringing in cooling gel packs and putting the venison in a soft cooler with them. Any suggestions or ideas I'm missing? Thanks in advance!