Question: I need to place a Wifi surveillance camera near the entrance of my house where no power outlet is in that area. 

I pulled a wire wrapping wire (awg 30) to the target location without thinking about wire resistance. And as you all expected, it didn't able to power the webcam.

The power the camera uses is 5V @ 1A.

I measured the wire resistance of my awg 30 wire to the location is 11 ohms (to and from) which is 6 ohms one way which is around 50 ft. 

So my question is what is the minimum gauge I need to use to be able to power my webcam placed 50ft away from the USB power adapter?

Or how many awg30 wires I need to pull to lower the resistance to allow enough power to pass through?

I assume the common practice is that the voltage drop is less than 5% of the required voltage. 

So 5% of 5V is 0.25V

R=V/I so to allow 1A to pass through the resistance should be 0.25V/1A = 0.25ohms.

From the chart:
<https://www.cirris.com/learning-center/calculators/133-wire-resistance-calculator-table>?

Therefore I need a minimum of one 14 Gauge wire (or a bundle of fifty awg 30 wires LOL) to power the webcam 50ft way?

Answer: 
If you really need to know, you should look into simulation.

You should also edit your question to include the signaling speed or edge rate of the signals.

But I think there is a good chance you will get away with it. Diff pairs primarily couple to the adjacent plane. They don't couple edge-wise to each other very much. So the deviation in spacing will have minimal effect on the differential impedance. The critical thing for differential pairs is to match length.

A few times I have done boards where I violated spacing rules in one or two places to help escape from a BGA. This did not incur major cost increase for the board. This was in high volume production.

So you possibly can route most of the board using 5/5 rules, and use 3 mil spacing only in the area where you escape from the BGA. This may not be a problem for the board vendor. You could investigate that.
If that region of discontinuityis << wavelength, then you are OK.

If your edges are 1nanosecond Trise, Tfall, and that region of bad Z\_diff is 50 picoseconds ( < 5% of the edge time) you will be OK.

And even the edge gets upset, the DATA EYE is what is important. 100pS upset in a 5nanosecond-long data-eye will be fine; the reflections will have long faded away before the receiver-clock strobes the receiver FlipFlop to make a decision.

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And if the reflections should occur in such a way as to increase the data-eye, like would be even better.

Beware of the signal energy stored in the ESD structures and the leadframe inductance of the package. Its is ISI -- inter Symbol Interference --- and may improve or may degrade the data-eye.