Short answer: Joe needs to become a mariner and ship-owner.
Long answer. I'm assuming that Joe knows the date of the catastrophe to within a month but has no idea as to its nature other than that it will be global. So Joe makes a list:
- Super-volcano eruption
- Nuclear War
- Killer Pandemic (natural or otherwise makes no difference)
- Large meteor impact
- EMP war or Carrington event leading to global failure of electrical infrastructures
- A runaway ecological collapse (faster than most expect; Joe knows )
The locations of dormant super-volcanoes are known. Don't be near. Nuclear targets will almost all be land-based. To catch a pandemic you probably have to be in contact with humanity at large during its ravages. Be isolated. Meteors you'll have to trust to luck, at least for now. Be mobile in case an astronomer gives enough warning. And following on from whatever catastrophe strikes, there will be a terrible period of starvation and war, until the human population has fallen 80%+ to a level at which the survivors can support themselves with whatever level of technology remains.
Best bet for survival is to be at sea in an ocean-capable vessel and to be able to stay there while the worst of the consequences on land work themselves out. A dozen people on a deep-sea fishing vessel provisioned with surviving these catastrophes in mind is about the best chance.
Provisioning: Spares for everything electrical that the ship can't work without, sealed in Faraday cages (in case EMPed). Solar still (water, though as a last resort one can get water out of fish flesh without a still). Lots of fishing lines and hooks (indefinite food supply). Vitamins, especially C, to supplement a fish diet for several years. Ideally the ship is an anachronism that has sail(s) as well as a diesel engine. Chronometers and Sextants and the knowledge to use them. Trade goods, for eventual landfall. A Faraday-protected PC, with all human knowledge on DVDs (Or at least a good encyclopaedia). Seeds, of old-fashioned crops that can be re-sown from last year's harvest. I won't go on. Joe has nearly 25 years to work it out.
Weapons? If I were Joe, not. Those who live by the sword die by the sword. Better to throw your lot in with the survivors once the megadeaths are over. Small isolated rural communities survive on cooperation not conflict.
Joe can openly be known as a bit of a survivalist "nut". He owns his ship. He makes a profit. No-one else believes in his apocalypse, but its his money he's spending on making his boat apocalypse-ready. He'll get amused tolerance if he's good-humoured. Much of the work also makes it one of the safer boats to be on in a storm.
Come the last month, Joe loads his few select loved ones on board (he's trained them as crew!) and sets out for the deep ocean. He sticks it out at sea for as long as he can. If there's anyone still broadcasting two-plus years later, he'll know the best places to return to land. If not, aim at a remote island with a low human population density and a tolerable climate. Saint Helena might be a good bet.
If becoming owner of an ocean-going fishing vessel within 25 years is beyond his abilities, next best bet is to emigrate to such an island.
Alternative involving such as island. If Joe has the gift of the gab, he can persuade a billionaire philanthropist to set up what might come to be called "The university at the end of the world" (only partly in jest). In normal times it would be a place where academics could take a one-year sabbatical to de-stress, think long deep thoughts, make the odd breakthrough, talk to other like-minded academics, and provide children in one of the world's most remote locations with a better education than would normally be available to them. It would also be well-stocked against the day that humanity finally and fatally screws up. Joe knows this day is coming but if he's smart he doesn't say this. Just points out that we won't stay lucky for ever and that the billionaire could arrange for a lifeboat out of the interest on his fortune.
Once it's up and running Joe and his family emigrate there as permanent staff.
By the way, if any billionaires are reading this, please do take this idea and run with it. Because we won't stay lucky for ever.