For extension cables, I like to recommend Windynation MC4 cables. you can also go together with two 100W panels wired collectively in parallel to enhance the charging speed.
Notice that I have paired the Yeti with 400W https://theresavxqp426311.ssnblog.com/27102139/the-smart-trick-of-best-portable-power-station-that-no-one-is-discussing