Which travel accessories are essential for Lumix M4/3 bodies?

Like someone mentioned, those Peak Design accessories are decent quality, but I have to disagree on the value for money there. It's a big investment for a single trip and you can probably save some cash elsewhere. You might want to consider a more budget-friendly approach for a light Lumix setup. Those Shell covers can actually be quite cumbersome with tiny primes because the fabric doesn't fold down well. I would suggest using a simple rain sleeve which is much cheaper and more packable... Make sure to think about power too. Iceland is cold and the G9 eats batteries when you're using the EVF constantly. I would suggest picking up the Wasabi Power DMW-BLF19 2-Pack and Dual USB Charger instead of the expensive OEM ones. They work basically the same for a fraction of the cost. For those waterfall shots, be careful with the super cheap filters as they often have a nasty color cast. I'd look at the K&F Concept 58mm Variable ND2-ND400 Nano-X for a good balance between price and performance.

I saw this earlier and figured id chime in since im really happy with my current low-cost setup. Iceland weather is pretty intense but you dont need to drop hundreds on accessories to keep things safe. Honestly, one of the best moves i made was picking up a couple SanDisk Extreme Pro 128GB SDXC UHS-I V30 cards. They have been totally reliable for me and i havent had a single failure even in the freezing wind. Usually i keep three on me just so i have backups... better safe than sorry when you are middle of nowhere. Since you are using those small primes, i really liked using the JJC Camera Wrist Strap ST-CP1 instead of a bulky neck strap. It feels very secure and cost me basically nothing. No complaints about the quality so far. Also, to save space, i just use a Tenba Protective Wrap 16-inch Black to pad my camera inside a regular backpack. It works well and means you dont need to buy a specific camera bag. Just wrap it up and you're good. If it gets really wet, i literally just use heavy duty freezer bags to cover the body. Works like a charm and keeps everything dry without the extra weight. You are gonna have a blast out there!

Make sure to get a Peak Design Capture Clip V3 for your straps. I would suggest the Peak Design Shell Camera Cover Small too, just be careful with the heavy Iceland rain.