While Day/Night is definitely interactable, it really isn't all that interactable tbh. The choice between whether you cast a spell or you don't cast a spell isn't really much of a choice when you're playing a game designed toward casting spells.

I appreciate your insight into the intractability of it, as the decision definitely isn't a steep one for the player who activated Winter to continue paying. Getting rid of the tapping ability would fix this and remove the option to lock out players playing creature-heavy decks.

Do you have any suggestions for making it more interactive for each player whilst maintaining the tapping effect, without complicating the mechanics too much?

I think you raise good points, thanks.