To the OP.
First off I am old and have an expensive truck that is used mainly for towing duty, otherwise it is in the garage.. I have other things to drive day to day.
That said. It really depends on how big a deal an unplanned battery failure is to you. At 5 years, your batterys best days are likely behind it, so each day forward means an ever increasing probability
of failure.
On my last expensive truck, the dealer noticed a slight leak on one of my batteries terminals, and swapped it out for me under warranty, while it was being serviced (without telling me first). I like to keep my batteries matched age wise, and told them so. They said that the warranty would only cover the faulty part.... After getting nowhere talking , I was faced with a decission. Risk the batteries almost 3 years different in age causing a failure, or bite the bullet and buy another matched battery.
Since I can afford expensive trucks, the cost of a battery will not cause me miss any meals..... And I am usually camped in remote locations without cell phone service, the decission was easy. I bought another battery.
Your circumstances are not my circumstances, so your decission may well be diiferent.
I will just note, that generally a failure will not happen at a good time.... At least in my experience.
As always, your money, you choice.