Get a 26800mAh battery pack with quick charge. It can charge your phone 5 to 7 times depending on your phone. Should be plenty for the whole weekend and much much much faster than any solar charger out there.

This is the one I use. It can even charge my Nintendo switch. https://www.amazon.com/dp/B01LRQDAEI/ref=cm_sw_r_cp_apa_JrmCBbP3CMYZQ

I should add, there are some inexpensive 3rd party docks that provide such things as USB-A and USB-C ports, HDMI, and ethernet, besides allowing you to charge via USB-C. Check Amazon.

I bought a high-capacity battery to charge it on the go and a PD-compatible charger that will simultaneously charge my phone and the SG. The stock charger works fine, but frankly it keeps disconnecting with the slightest jostling (it connects magnetically). It's also not compatible with anything but another Surface.

https://www.amazon.com/gp/product/B07VLKKRP7/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B01LRQDAEI/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1