Therapy pool in greenhouse, Dome, high tunnel or ???, input welcome

I am trying to make the best choice for us on a greenhouse and figured this was the group to ask for suggestions and input!
We have moved to a nearly 1acre lot in a semi residential area. Getting approval for a large greenhouse will not be a problem.
Top priority for us is to have a hydrotherapy pool that can be used for as much of the year as possible. This aspect  will be the priority for likely only the next 5 years, 10 on the outside. Secondary is to do seed starting and overwintering of some things like citrus, figs, herbs and other plants. I'm on board with a few permanent residents like a passionflower, mango or papaya, if possible. Otherwise, probably melons, peppers and tomatoes in there in the summer months.
I've looked at pool options and a basic above ground style seems like it will do what we want. I may look into ones where we can insulate the sides and top.For this plan, being able to cover it would be good, I think.
The property has a good, fully exposed, south facing spot that could fit a large high tunnel greenhouse, in the 24'x50' range or something like one of the 32' domes.
There is no way to do an earthsheltered gh, due to the property shape and the ground is sandy with very high water table so digging in won't work. Also can't attach it the house due to the back layout.
While I would love to do full passive solar, I am not capable of doing the build myself, we need it asap and it looks like pricing would be at least 2x or 3x the other options.
We deliberately bought the place we did so we would have a budget to do this but keeping the price as reasonable as possible is, of course, preferred.

At present, I am leaning towards the high tunnel and going with the suggestions from the tiny house thread and arranging to get straw bales each year that we can stack along the north wall and then I can use them in the garden every spring.

Any imput welcome!

This sound like wonderful space in the making.
Between woodfired pool heaters,insulated pool covers, and solar pool heaters, you have a lot of off the shelf options for heating the pool.
Will pool maintenance be a challenge?
What about accessing the above ground pool?
Will ladders be adequate or will stairs and a deck be required?

If your zone 6 is any like mine, you will want shade cloth in the summer.
You might benifit from silver mylar bubble wrap insulation on your north side.

For pool access, we'll likely go with a basic set of stairs and then a pool lift for the mobility issues. ( might have to buy this new but I have hopes of getting lucky in the resale market)

I feel pretty comfortable with the maintenance. We've had family with them and know what's involved and it being mostly enclosed should cut down on a chunk of the issues.

Shade cloth is very possibly going to be needed. I keep looking at the "Chinese" style passive solar ones with rolled rattan shades and thinking I might be able to get something like that to work.

Insulating the north/east/west sides is the issue. How to do it in a cost effective manner is going to take some thought and luck. The Mylar is very possible.