中翻英：该由你来决定我们明天去不去远足。(up to )

It's up to you whether we will go hiking

It's up to you that if we are going hiking tomorrow.
It's up to you that if we will go hiking tomorrow.

远足还可以用excurse, jaunt, walking tour.

It should be up to you whether we would go hiking (or not)tomorrow.

it's up to you if we to for travelling of not.

It's up to you to decide whether we would go hiking