Questions about performances.

In the game i'm building, a user should have a pack of cards which are not visible on the screen but is chosen at the beginning of the game and can be access at random times in the game.

So the question is:
If I'm changing their rectTransform position to be outside of the screen ( x:-1000, y:-1000 for example ).
Will it still calculate them?
If so, If I'm using the canvasGroup component to lower it's alpha to 0, will it calculate them then?
What is the best way to have unused and unvisible ui elements on the screen ( Only have their reference stored in an array/list for later use ).