Charlie is on the money...This is a topic I have researched a bit ( having retired at age 57 a few months ago) and my response will probably not be what you would like to read but it is based on the experiences of a number of people who I have spoken to.
There are issues with leaving wherever you are now to retire and going to an idyllic location like Hervey Bay or anywhere else. (BTW, I lived at Hervey Bay for three years 27 years ago and it was wonderful! I also lived on the Gold Coast for a while and the traffic there made it like living in New York - hardly idyllic at all!))
The issues relate to support structures, family connections and your sense of community.
Often a couple will retire to a remote locale and find that they are disappointed because they no longer have their familiar infrastructure - eg their bridge club or bowling club friends who they have known for years and years. Loneliness can set in.
Often, everything will be fine until one of them dies or becomes infirm and without the support of family around them, it is really difficult for the remaining spouse, or healthy one as the case may be.
Similarly, grand-mums, in particular, miss seeing their grand-children and when the family is back in the big city and you are living in paradise, you will be the ones traveling to see the grand-kids, not the other way around - at least not after the first year or so. Families, especially when they enter the teens have their own society and world of weekend sporting and social events that will keep them in the big city. Likewise, their working parents are likely to be so buggered at the weekends that they just want to flop at home and not load up to take the grand-kids visiting the oldies four or five hours drive away.
The real tragedy that besets so many people when they sell up their long-time home and move to a far off place to retire is that when they do decide to leave paradise and return to the big city, often they cannot afford to do so. Real estate prices have moved and what they can afford is a modest unit or retirement home - not quite what they had in mind.
Talk to your friends who may have moved somewhere in retirement and see what their experiences have been - but only those who have been gone three years or so - after the halo effect of the new location has subsided.
Buying and selling homes and shifting costs a lot of dollars. Those dollars might be better spent on some long off-season holiday rentals in paradise but still having your home in its familiar environment to come back to.
If the old house in not quite what you think you need in retirement, you can always renovate.
stay where you are near to family & friends & take extended holidays as required...become grey nomads..