Hi @Rocket_Napoli - Thanks for reaching out!
Unfortunately, we used to carry a few options for overboots but no longer do.
While you will have to purchase those outside of REI, we are hoping community members will have some recommendations for you on which options are best for your Arctic plan. @hikermor, @RobertH, @Andrew-Lock , @TM - have you all used overboots in the past to save weight on expeditions? Do you have any feedback to offer Ben?