That was our plan years ago, but the Pyramid building society crash put paid to that...... & we were so close!
There are plenty of young families out there doing it, & when you are younger it is easier to 'rough it' a bit more.
The family that sticks in my mind was Mum, Dad & two kids travelling in an old beat up old FJ (I think) Cruiser. Running it on used veggie oil. Met them at Uluru. They had just come across from Laverton, had been to the hotels/cafe at Uluru & managed to get a heap of used cooking oil & were in the process of straining it for use. It was a hard way to travel, but they were out there & doing it, rather than sitting home watching the idiot box. The kids, both under 6 were having a ball.
There are folks from all walks of life out there seeing the country, from those in the huge mansions on wheels, to the pensioners who camp up between pension cheques, & then move on as their shoestring allows..... & everything else in between.
When we eventually take off again (when, not if) we expect to have a reasonable 'nest egg', but hope to dip into it as little as possible, finding casual work, & house/farm sitting as much as we can. Some folk sell up everything, but we all need more or less in terms of a security blanket. For us it is essential to have some sort of homebase we can return to if our health dictates the need.
One couple we met had worked the season at a beautiful & remote resort, making beds, cleaning toilets etc. low hourly rates, but all food accommodation provided (along with living in a fantastic place & a few perks - like free tours etc). When the 5 month season finished they had saved enough to continue travelling for the next 7 months.
We had lots of worries about the 'what if's' before our big trip ..... But it's amazing how silly most of them seemed once out there & doing it. Worries about extended family - stay in touch just the same. Nowhere is more than a day or two away in an emergency. Worries about mechanical breakdown - tell me about it - ours was about as bad as it gets - thankfully we had budgeted for an 'emergency kitty' which we hoped not to use, but which paid for a replacement motor in Katherine. Worries about safety - often a big one for some - all I can say is that in 18 months on the road we never once felt threatened or unsafe - it's a state of mind as long as you use a modicum of common sense. There are probably many other worries, (believe me , I'm a worrier!) but they really all just melt away once the reality of life on the road kicks in.
As a result of my blog, we had all sorts of people following our trip, & it wasn't uncommon to receive invitations to visit from strangers when in their neck of the woods. Often this was because one partner wanted to 'prove' to the other that 'normal' people were in fact able to travel like this & survive! As part of the 'convincing' process.
Maybe suggesting to your wife that she read my, or other travellers blogs might help.
All our circumstances are different, but for most, us included, if you don't do it before the kids start school, it is likely to be a long long time before you do manage it.
All relationships differ too. I was the one who drove the desire to travel. MrsTea wasn't keen, she has always tended to be a 'homebody'. However she recognised it was my dream & reluctantly agreed. When I got cold feet shortly before taking off, it was her that pushed to keep the dream alive.
After the first few weeks of adapting to being together 24 hours a day & life on the road in general, she started to enjoy the thrill & freedom of a different million dollar view each morning. By the end of the 3rd month, we were both knew that when referring to 'home' we meant our bus. The trip changed her outlook, although still a homebody she now recognises that 'home' does not have to be in one place, & the dream to travel more is no longer just mine, it is our shared dream.
We only get one life.
Cuppa.