Need more input!!!
Is it 1 floor at 2600 sqft? 2 floors at 1300 sqft?
Where are you looking to rent? Maine? Tennessee?
Best thing to do for utilities is to call up the utilities and ask them how much utility costs were the previous year during those months.
You can also ask the landlord or current tenants. I am a landlord in Medford, MA, and whenever I have to rent out the place downstairs, I always have to answer that question. Asking the people that are actually involved will probably be more helpful than asking a forum of people spanning the Northeast. Still confused how Mr. Chattanooga ended up answering...
Also, your landlord isn't allowed to charge you for water. Water/Sewage is included in rent.