If I put electric heating cable under the granite floor before it goes down, an area 48" x 96" would cover all areas normally walked, a few inches under the toilet, and within an inch of the sink for washing up. A corner behind the door and a corner beside the toilet would not be heated. Under the washing machine would not be heated.

Maybe (big maybe) some areas I could go 46" or 50", but I suspect that the heat would radiate an inch or two out, and also that my toes will not likely freeze solid and fall off while I stand at the sink.

Would heating cable allow me to zig-zag by a few inches?

Is mat or cable easier to install?

Is there any reason for choosing one over the other?

Is any brand well reputed? The Solar or Sun cable one (oxygen-free) is easy to buy here. Nu-Heat is also available.

If all you have to heat is a basic rectangle and a Nu-Heat mat fits, that would be the easiest to install.
If you have odd shapes to go around then the wire system is better.

With wire, your going to have to skim coat it or use a self leveling cement to cover the wire.
Usually with Nu-Heat you can just start laying tile without skim coating. If your planing on using Schluter Ditra, then you will have to skim coat anyway.

Personally I prefer the wire systems, but thats mostly due to the room layouts I'm working with and the mat systems have always been more expensive to cover those types of areas.

I'm not familiar with Solar or Sun products. I use Easy Heat or Flextherm.
Nu-Heat is a very reputable product. They also have a wire system.

Randall, thank you. Yes, Ditra will go on top of the floor heating system. The person who will put it in thinks that it will be easier with the mats. The 2-inch difference is all to do with how close I put it to the toilet's wax ring (they say to leave a few inches). The sink is in the same plane (both back onto the same wall), so closer to the sink is closer to the wax ring.

SunTouch is the cable type that is sold here (Reno-Depot). Someone here posted about liking them (oxygen-free cable). For NuHeat, mats and cable from http://www.tile-experts-canada.com/ and also probably from Home Depot.

Using the mat, maybe one or two (if not available in the exact size) sounds like the easiest thing to do. Tile Experts will order a custom mat, says it takes about a week.

It takes me about 2 hours longer to install a cable system as opposed to a mat. When you take into account that cables are about 20% cheaper than mats, the overall price is fairly similar. Like RC said, if you can fit an off the shelf matt then that's what you should go with. It's possible to modify a mat slightly by cutting between the cables and moving them a bit closer together to wind around the toilet. I checked with NU-heat on this. Their cables are roughly 2 inches apart and they allow them to be moved to about 1.5 inches without voiding warranty. This lets the mat to be modified by an inch or two if need be.

Thank you, Pete. Yes, my renovator friend who will do the installation said he could fidget the inch or two. Squishing them together around the toilet, for all of a few inches (to go around the wax ring) is perfect. The full spread then takes it right up to the sink, where I intend to stand on warmed tile to shave and pull nose hairs.

That is great to know that the NHeat mat is a 2" spacing and that they do not object to fidgeting with the mat. I will pass that along.

You know, the 2 hours is worth more than the cost of it, because I can only get xx hours done in any week. Everybody has other things to do, including me, and time off work is starting to be dicey.

call Nuheat technical support for the exact spacing reduction they allow.