What is the best all-around zoom lens for Micro Four Thirds travel?

Hi everyone! I’m currently planning a three-week trip through Japan this fall, and I’m trying to streamline my Micro Four Thirds kit. On my last few trips, I found myself constantly swapping between primes, which led to a lot of missed shots and a very dusty sensor. I’ve decided that for this trip, I want to stick to one high-quality "do-it-all" zoom lens that can stay on my camera 90% of the time.

I’m shooting with an OM System OM-5, so weather sealing is a big priority for me since I expect some rainy days. I’ve been looking closely at the Olympus 12-100mm f/4 IS PRO because the focal range is incredible, but I’m a bit worried about the weight and bulk for 10-mile walking days. On the other hand, the Panasonic-Leica 12-60mm f/2.8-4 seems like a great, compact alternative, though I’m curious if I’ll miss that extra reach on the long end for architectural details. I've also considered the 14-150mm super-zooms, but I’m worried I might sacrifice too much sharpness and low-light performance.

I really want to find that perfect balance between portability and image quality. For those of you who travel exclusively with MFT gear, which single zoom lens do you find provides the best versatility without becoming a burden to carry all day?