I believe there may be a transport aircraft with an air drop-able life raft as an alternative to the one man raft that comes with the ejector seat. Other than that careful routing to take the shortest distance while remaining in cover of air sea rescue. This isn't a major disadvantage as the route should also allow aircraft to divert to a suitable airfield in the event of a problem with the air-to-air refuelling which will often coincide with an air sea rescue base.
My understanding is that they generally plan on no aircraft going below ~50% fuel to give a decent diversion range and a bit spare for a contingency. This does mean they have to refuel more often than you'd expect if you just used the basic range figure. Obviously having a thunderstorm in the way makes it a lot harder to guarantee you'll manage that.