ANSWER - I often feel that the witches in the Southern Hemisphere get a bit overlooked and both my site and others are guilty of wishing everyone a happy Yule without considering that the witches down under are celebrating Midsummer. However the whole sabbats thing can sometimes feel a bit prescriptive, no matter which hemisphere you happen to live in.
Indeed some witches find the structure of eight sabbats just too prescriptive a framework. It is important to realise that none of these festivals are in any way mandatory or essential to either the practical or the spiritual life of the witch. Following a strict calendar can actually be counterproductive as worship (or celebration for the secular witch) can as a result turn into a duty or an obligation which defies the whole idea of festivity.
Many witches choose not to observe all of the sabbats and many don't observe any of them at all. Observing all eight festivals and the wheel of the year is more associated with Wicca than witchcraft per se. Although Pagan witch paths will usually acknowledge the solstices and the equinoxes there is no imperative for elaborate ritual. The degree to which you choose to mark the occasion is up to you. Whether its a full scale coven meeting or a quiet glass of wine in the bath, if your choice has meaning for you then that's what counts.
I think the calendar has come to mean more than it should to the modern witch. There is too much emphasis on what exact day changes of the year should occur on and to an extent this dismisses the natural instincts of the witch. I would suggest that instead of following a list of dates you acknowledge the changes as you feel them. As a witch said to me this year - It's hard to celebrate Imbolc when there is still snow on the ground... And she's right - this year the birth of the Spring was a lot later than tradition would normally dictate. Why not have some markers of your own as to when you personally want to take the opportunity to mark change. The first crocus perhaps or even that first day when you sense the change of seasons in the air. React to your actual environment, not to what you are told to observe and you may well find you get more out of the sabbats.
Personally speaking I don't observe all the sabbats equally. Same with the moon cycle, at some times the moon has great meaning for me, at other times I'd be hard pressed to tell you when the next full moon is. Some years one sabbat may be celebrated with pomp and ceremony and other years it may pass by virtually unnoticed. I don't feel obligated to celebrate unless there is meaning and reason to do so and I'd advise the same to anyone else.