The simple answer to the question of how big your handbag needs to be is that it depends on both personal preference and a great many other factors. The good news for handbag lovers who have to justify their collection to others, is that you definitely need more than one.
Handbags and purses are very personal items. Some people prefer great big ones, so that they carry their lives around with them, whilst others prefer something small and simple, which makes any contents inside easy to find. However, on certain occasions, a different type of handbag is needed. For example, it would be wrong to turn up at an elegant evening party with a great big leather handbag; etiquette dictates that it really should be clutch or small shoulder bag at such events. Similarly you probably wouldn’t go for a long day of outdoor activities with one of your small luxury bags.
For long days or overnight stays it is worth investigating in one of the many stylish holdall options rather than trying to cram all your belongings into your handbag as you may risk damaging it. Unfortunately, or perhaps fortunately for some, you really do need a few handbags of different sizes.
For everyday usage, such as shopping trips and causal activities, the choice really is up to you and the final choice may well depend on what you plan on storing in your handbag. However, it is worth having a few bags of different sizes on hand so as not to get caught out when a different sought of engagement is sprung on you at short notice.