All depends on how important it is for you to be at your final ticketed destination on time. You haven't even told us where you are headed, let alone whether it matters when you arrive.
Generally, you will not be rerouted until a misconnect occurs because aircraft often make up time enroute, your connection may be delayed, or the delay may not be sufficient to cause a misconnect.
If you do misconnect, it will be for BA to either provide or reimburse a hotel and meals and to rebook you the next morning. Unless the delay is for an "extraordinary circumstance" you will also be due delay compensation of EUR 600.
If indeed you arrival into your destination is time-sensitive, I would do what it takes to make it. But, otherwise, let the chips fall where they may.