Which Canon RF lenses are essential for landscape photography?

What are the absolute must-have Canon RF lenses for serious landscape work because I am honestly losing my mind with my current setup? I recently switched over to the R5 for a huge solo trip to Glacier National Park next month and I thought using my old EF-to-RF adapter with my vintage glass would be fine but it has been a total nightmare lately. The autofocus keeps hunting even on a tripod and the weather sealing feels super sketchy whenever it starts to drizzle and I am just so fed up with missing shots because of gear glitches. Im literally three weeks out from the trip and I have about $4500 left in my budget to just get native glass that actually works properly. I mostly do really wide vistas but I realized on my last local hike that I really missed having some reach for compression on the distant peaks. I was looking at the 14-35mm f4 because I dont really think I need f2.8 for mountains but then everyone online says the 15-35mm is way sharper at the edges? I just want something that wont fail me when I'm out in the mud and wind. Do I need to bite the bullet on the 70-200 too or is there a better way to cover the long end for landscapes? I'm just so stressed about this trip and I dont want to waste more money on lenses that are gonna let me down...