I have over 20 and none have dropped their leaves...so I'm not tempting fate. A lot of my hibiscus are in pots and they hate to be wet and cold. I barely water them during the winter. We're about to get rain tomorrow or Monday.
I was out yesterday, trimming and tossing. Saw lots of new growth under 'dead' salvias, so I'm feeeling a little better about the front yard. Didn't get around to building the berm over the winter....maybe next year!