I'm sorry, but realistically, you can't.
That being said, if you look at the range of different "fitness" qualities (endurance, power, strength, flexibility, etc), strength is generally the last one to go, and it's also one of the easiest to get back once you've initially built it.
There are some things you can try, there is going to be some carry over from bodyweight exercises to the traditional powerlifts (though obviously not as much as training the lifts). Things like dips and pull ups to strengthen the triceps and back. You can do core work because a stronger core is always a good thing. Pistol squats, while not the same as a loaded barbell squat, will allow you to keep training your legs.
Also, now is the perfect time to address all those little niggles and flexibility issues that you've been ignoring. That tight hip, the knee that aches if you keep it in the same position too long, the shoulder that's a little wonky, everything like that.
Fingers crossed, by fixing the little bits and throwing in some bodyweight stuff now, you'll be able to come back stronger (figuratively speaking) when you're able to get back to training.