There's no bottom limit, but the wallet needs to be open. Thing is, at this point with 110 burnt you'd get about .5 slim a day, which means about a month for a block on average.
edit: although if you burned them months ago and haven't gotten any PoB blocks, I'm guessing you aren't leaving your wallet running 24/7
It was 16 of October exactly. The wallet is 24/7 and staking OK, will wait and see, thanks!
Ah so about 3 weeks- that makes more sense. Good luck

If you have any issues with the wallet taking stupid amounts of memory you might consider updating to the newer one- it doesn't include staking, but it's more stable and uses fewer resources.