Just found this thread. Im super satisfied with the Canon RF 24-240mm f/4-6.3 IS USM for travel. Honestly, it works well and I have no complaints. Its way under your budget, so you'll save plenty of cash. Focus is snappy on the new bodies and it covers everything from wide shots to telephoto without swapping glass. Its much lighter and very reliable. Definitely worth considering if you want one lens that does it all.

tbh sticking with that old glass on a beast like the r5ii is just asking for frustration. if youre going to iceland, you really dont want to be swapping lenses in the wind and rain. i would suggest looking at the Canon RF 24-105mm f/4L IS USM because its way more reliable. it stays under your 2k budget and is way lighter than the old ef setups. few things to keep in mind:

• make sure you get a decent filter for the front because icelandic sand is brutal
• dont expect the f/4 to be amazing at night for aurora, youll definitely need a tripod for that
• the autofocus is gonna be night and day compared to your old brick... its basically the perfect travel lens for that body. just be careful with the zoom creep over time tho.

Just saw this. I had issues with my setup last year and it was honestly not as good as expected. Focus hunting on older glass is a total nightmare. Unfortunately, I even ruined a sensor once because moisture leaked through a weak seal. You should check the weather sealing reports on The Digital Picture before buying. Just dont risk non-native glass in Iceland... its basically a graveyard for gear.