Well as I said in my above post they worked fine for us and in some lousy weather. However we not on all year pitches. Given that yours will be pitched 365 days per year it will in all probability see more bad weather. No storm straps can guarantee that nothing will happen. Much depends on where your pitch is, where is the direction of the prevailing winds, is there any firm of windbreak such as a hedge or adjoining buildings, if the weather really soaks these grounds pegs can begin to slacken off. Can you use the long 12 inch marquee pegs around the base of the awning? But Isabella kit is good and has a fiene reputation. Will the site owner keep an eye on things? How often will you be over to the caravan, and if the forecast is bad how quickly can you get to it.
This may be a bit pessimistic but I'm sure others on the site will guide you. And if there's a problem then neighbours generally help out.