Building on the earlier suggestion, that clip is gonna be your best friend on the trails! Since youre trying to cut down on bulk and save some cash, I found a couple budget hacks that might help you out.

• Wasabi Power Dual USB Charger for Canon LP-E6
• This is fantastic because it's super light and lets you charge your batteries via a power bank inside your pack while you hike.
• Joby GorillaPod 3K Kit
• Love this for the 90D! It is way less annoying than a full-sized tripod but still strong enough to hold your gear for those amazing waterfall long exposures. I'm so excited for you! Iceland is totally mind-blowing and youll love what that camera can do there. Just keep those extra batteries tucked inside your jacket to keep them warm against your body. Youre gonna have a blast!

Unfortunately, I had issues with fancy trekking packs being way too heavy. Not as good as expected. Ngl, save your cash.

• Dont buy clones; Canon LP-E6NH Lithium-Ion Battery is the only one that survives the cold.
• CADeN Camera Backpack L5 is cheap and much lighter.
• Keep batteries in your pockets with HotHands Hand Warmers 10-Pack so they dont drain.

I'd suggest using the Peak Design Capture Camera Clip V3 for better weight management. Please be careful with Iceland's humidity; the Peak Design Shell Camera Cover Medium is a necessary precaution.