Tried to do a bit of searching, just out of curiosity, and it seems like there is a big gaping hole on the US market when it comes to all-weather snowflake-rated highway SUV tires... Since you don't want regular AT tires you have pretty limited options if you want a single set and drive in snow :/
I recommend you take a look at Nokian all-weathers (WRG3, Rotiiva AT) and also the Toyo Celsius all-weather tire might be available for your truck, not sure. KO2s are overkill for you, Hankook Dynapro ATM too - but both have the snowflake symbol. GEOLANDAR A/T G015 and Discoverer A/TW are both snowflake-rated as well and seem to be a bit on the less agressive side of the AT spectrum (the same applies to the Rotiiva AT and AT Plus which really are great tires in snow from what I've read - I researched them but had to let them go because they don't - and won't - make them in 255/55/18).