To be sure that you'll have the cards when the season ends, the most reliable, safe alternative is renting when the season end is in less than 23 hours: a rental can only be canceled by the card owner after 1 day, so you guarantee that you'll be with the card to receive the season rewards.
In theory you could rent when it's 23:59 minutes; I would give an extra 1-2 hours just to be sure in case the server borks and things get slow for a while.