Before the first spin, the bonus timing stays open
Deciding how long to keep spinning for the bonus round is a choice no one can make on facts alone. The bonus round comes at random, and no spin count, streak or pause tells you when it will land. Whatever the RTP version, one session ends with a result you cannot predict, since every spin stands on its own.
Choosing to trust the return figures starts with knowing which RTP version runs here. That is shown only in the game rules, not on the reels. The RTP figure describes the long-run return of the game, not what one evening will bring.
Expecting much from the top prize is a choice worth checking against one fact. The maximum win of Fat Santa, x11,322 of the total bet, is a ceiling reached very rarely, so treat it as a limit to know, not a result to plan on.