I live in the SF Bay Area and I've had my 285/70 /17 Load C KO2 for 13 months. I have 12,000 miles on these tires and haven't experienced any issues in the rain.
I have this bumper and I had to bend the front edge of the oem skid plate and use washers for it to fit.
The removable CBI decorative plate allows you access to the 4 mounting holes to install a winch. I have a Warn vr evo 10s installed on mine.
I'm running 275/70/17 Falken wildpeaks at3 on trd pro wheels with 1" Bora wheel spacers. I have 6112 and I'm lifted about 2.25" up front I also have JBA uca set at 4.8 degrees of caster. I had to do some front bumper trimming, wheel liner mod and removed my mud flaps. I still slightly touch...
I have Falken wildpeak at3w in 275/70/17 on Trd Pro wheels 4mm offset. All I needed to do was move the liner forward and trim a small portion of the front bumper, doesn't rub on the mud flaps on road or off.
I do have a 2.5inch front lift and Jba UCA with close to 5 degrees of caster, so YMMV.
I agree, the cold temperature and flat spots are causing the vibration. My Falken wildpeak at3w load C seems to do this more than the factory Bridgestone Dueler.
I had the same issue when my 2017 was brand new and a wheel alignment at the dealership was the cure. Caster wasn't within specs at 2.5 degrees so the dealer brought it up to 3.