Gorilla pod becoz it is easy to carry , can be used in uneven ground ( this is the most important advantage of it) only disadvantage of gorilla pod is height which can be compensated by using table, some rock etc
Depends upon the weight of the camera you use. for a heavy camera tripod will be better option since it gives you stability against the strong winds. If u find it a hassel to carry tripod around and your camera so doesn't weigh much then go for gorillapod .Hope to have cleared your doubt 😄
Tripod anyway because the gorilla pod has a height issue so you need to keep it at a high vantage point to capture eye level portrait shots. So tripod, as height can be raised and lowered.