Starlink Mini averages around 20W during operation. I have one mounted on my truck, and use a foldable 200W panel when in remote areas (to also charge the aux battery and power other electronics). When folded it's about the size of a briefcase/small backpack. A smaller panel would certainly be enough for just the Mini.

The 200W panel: https://www.renogy.com/products/renogy-400w-solar-panel-blan...