Also have you talked to any property management companies to get their take?  

Websites like AirDNA can sometimes provide insights into average expenses for similar properties.Consult with Local Experts: Reach out to property managers or owners of existing STRs in the area.

Build cost 2 million ($240 per square foot for a 5400 square-foot duplex) (Sale price $650 per square foot valuating the duplex at 3.5 million) Upon stabilization, the properties market value is projected to be between 4.5 and 5 million.

We currently self manage.

Does anyone have a pre-built spreadsheet available to run projections for the sale of a house? 

Make sure you've looked into all of the financing alternatives that are out there and that you know exactly how much each will cost.Especially if you intend to rent out individual rooms, create a comprehensive management strategy for the property.

You also need to consider the effort and time required to manage a short-term rental compared to a long term. 

It is imperitive to budget for the phantom expenses such as capex, repair, maintanence, and property management (even if you are self managing).

Investing out-of-state can be even more risky if you do not have experience successfully underwriting, buying, and managing rentals.

The property is about 3 hours drive from my primary residence and I go there once or twice every week to work with my contractors to coordinate and manage the renovation.