Seeing that it was a dealership, I am assuming a car dealer here, but regardless you may have an environmental issue on your hands. 

The remediation company will not give an absolute move out recommendation, because they refer to a third party company for environmental assessment (minimum 300-1200 not covered by insurance), but the tech has indicated it would be a good idea for them to move out for 5-7 days.  

Is there a good educational element as well?

The house was vacant and sat open to the elements for 8 months in Utah and it was over the winter.

Such are not marketable.Contaminated properties are high on the list to stay away from, environmental issues can be very expensive to clean up. 

You would obviously have to factor in demo costs of existing structure, any environmental abatement etc, however that would be my first approach on establishing quick value.  

The following is a partial list of things that wear out or become outdated over time and eventually need to be replaced for every property:-Roof-Siding-Hot water tank-Furnace-A/C system-Electrical system-Plumbing system (inside)-Sewer service line-Water service line-Any concrete exposed to the elements (sidewalks/porches)-WindowsIf you calculate the cost of replacing each of those items and divide them by the expected useful life, then sum that up, you'll come up with a monthly amount that you can expect to spend on capex over the long term.

these are key elements in the discussion

While it doesn't have your kid element, our story does have the crazy predictable components of life.I too am looking for an opportunity to work on this full time so we I can stay home and raise our future kids.Feel free to pm me if you want to talk.

The simplest is to work with a turn-key company, which has all the elements in place from finding the property, to rehabbing it, to placing a tenant, to managing it.