I just hope there isn't much mold or frozen pipes that cracked since the home has been sitting vacant for about two years.

Ever since we closed on this duplex my mind has been thinking about the next move, we have saved up some money but I don’t know how to leverage our current property and turn it into a second duplex, I feel a bit frozen and would love some suggestions as to how we can start growing, what should our next step be? 

My limited experience with HELOC's is they can be reduced or frozen and as a result the money can end up being unavailable at an in opportune time. 

I've seen others have funds stolen, paperwork destroyed when they fired the PM, bank accounts maliciously frozen, and other things along those lines.

If there is any way to insulate the crawlspace that would probably help as well.Have those pipes frozen in the past? 

Frozen pipes aren't fun. 

They fear what 3 months of what damage or frozen pipes, or broken windows could do to a property. 

However, if you sell the property:3 - $40k equity/frozen cash is now defrosted and = $40k cash/liquid (loan payoff from mortgage pmts covers closing costs)4 - 20% DP = $40k; New PV = $200k (back to a 5 to 1 ratio); New CF = about $8k +/- (assuming you bought 2 of the same properties like the original property when first purchased).Losses by not selling:5 - $80k in PV; $4k/yr in CFContinue to repeat this process, and you will grow faster, exponentially...without having to access more cash from others.

Imagine a TK operator there who runs 100 properties, all with frozen pipes and no electricity.

Is there anybody building there or has the market frozen up?