How long can you leave a rabbit while your on vacation?

my rabbit gets about 8 hours of out time everyday and I have put her in her cage when I go away for 24-36 hours and she is find with enough food and water (that cannot spill). I often overfeed her so she knows not to stuff herself every time and saves some of the food for later. I have had her for 4 years and done this 3 times and she is always fine when I come home