Just send the break down of utilities.

Currently Rents out for 1200 per month, all utilities included, cutting my living expenses in half.

The strategy I plan on utilizing once I get through the Winter season is to send a rental increase package explaining why a rent increase is needed, showing comps of current market rents (for instance, using rentometer), and offering a few different options such as a year lease at a reasonable price, a 6 month lease at a higher price, and a month to month at a slightly higher cost.

That's great you were able to save up 35k, which is a fantastic place to start and you can utilize a low down payment mortgage.Denver metro has a lot of great pockets that work for your goals with price and proximity to the mountains and the city such as Lakewood, Wheat Ridge, Arvada, west Denver (west of I-25), Westminster, Thornton and Northglenn.

Sometimes including utilities. 

That may not JUST be confined to the rental amount owed, but rather utilities, late fees, etc BUT that varies from state to state and you'll want to consult your state's Tenant Landlord Act and related laws.

I will honor their current rental agreements but plan on increasing rent as much as 70% (owner was paying utilities too) with the next agreement. 

Then you have the utilities which can add up until you get it rented.

Then you could also get another STR somewhere else, as you could utilize a low down payment loan on the primary.Denver is a great area to invest, and I always prefer investing in your backyard!

The 50% that was saving each month for the down payment, now covers the Morgage and utilities, and with the phantom cash flow coming in now, it can now cover part of the mortgage as well.