Our concern is that it seems to be a decade or so before everything is settled in and producing in a permaculture set-up. Is that an accurate perception?
Like almost everything else, asPaul would say, "it depends".
True, a permaculture setting cannot be set up "as soon as the soil can be worked in spring". Your main 'kitchen garden' can be.
That is a first step that can be repeated each spring for your annuals. That will ease the burden of feeding yourselves until the perennials can kick in and provide a less labor intensive way to put calories/nutrition in the kitchen.
The time frame depends on many factors: climate being one of the most important.
Extremes in weather will determine what can/cannot be expected to perform in your location.
If there is
any commercial agriculture in your region, then it is suitable for growing a substantial portion of your food needs.
As Brenda pointed out, concentrate on the things you already buy and eat. But don't overlook things you don't currently buy/eat.
For instance, I've seldom bought winter squash. But it is an easy plant to grow, and produces a lot of food. It is also loved by chickens and hogs, so if you plan to raise either of those, the squash will provide many healthy meals for them when winter shuts down the garden.
Once a kitchen garden is established, begin getting your perennials established. While they may not be 100% settled in, they will begin providing food in a year or two. They will just get better over time.
I like your retirement plan, I'd imagine there has to be ways to speed things up, I would start with building the soil. It always starts with building soil... 
1
