Options for lower gearing on Shimano 105 2x11

Hi everyone,

I have some Alpine adventures planned for the summer, so I'd like to install some lower gearing on my bike, ideally down to 1:1. After a bunch of googling and investigating, I am still not sure what possibilities I have and what would be the most cost-effective option, so I am asking for help!

My setup is a full Shimano 105 from a few years ago, here the details:

• Front derailleur: FD5800
• Crankset: FC5800, 52-36
• Rear derailleur: RD5800, I can't tell if short or long cage, so here's a pic
• Cassette: 11 speed, 11-28

I understand the options are:

• Replace the cassette: but how big of a cog can I fit, I doubt it can be as big as 36?
• Replace the chainrings: but will that require FD adjustments; do I need to replace both or just the small one?
• Replace the crankset: also not sure about FD compatibility here

Hope someone can help!

Thank you.