I have had my Hobie less than a year and I`ve already had the boat lift up in the wind (while secured to trailer), turn 90 degrees and travel about 20 feet. It did this in what was reported to be 60 to 70 mph gusts. Thankfully, there was no damage to the boat or my wifes car - which it missed by less than a foot.
For winter storage, I have the trailer tongue elevated on a saw-horse to drain the hulls (plugs out). The tongue is also up against a fence post to which it is securly tied.
As for tarping, I left the tramp in place and covered the boat with one of those custom Hobie covers. In addition, I secured a 4 ft vertical support (for the mast) on the area of the rear traveller track. The support looks like an inverted "T" made from 2x4`s. It has large, thick rubber pads where it contacts the rear traveller track. This device supports the mast at about the same height as the mast support on the trailer. Once in place, the supported mast creates a central beam down the full length of the boat. Over this entire structure I placed an 18 x 24 foot tarp secured with bungees at every eyelet. At the front of the trailer, the tarp is secured to the ground with bungees using one of those (corkscrew) dog stakes Nick referred to.
Although I have not wintered my Hobie before, I do use the same technique on my 36 footer - and a 28 footer before that - I have never had any problems.
Dave