I see no reason to live anyplace where it stays really cold or there's much in the way of snow. I've lived rough enough to know that both are a huge, dangerous pita.
We are way, way, way out in to YMMV territory.
I'm trying to imagine a life without snow and without skiing and without cross-country skiing in particular and it is an unbearably sad thing.
as for your 2nd paragraph, an emberlit is in lieu of bringing a canister/alcohol/white gas stove strictly for boiling water for dehydrated food or actual cooking...i don't know anyone (real world or here) that would bring any of those and leave behind shelter and clothing and use it as their main source of warmth.
if you're referring to my shelter stove then you failed to read the "nice to have"...or you misread it as "must have"? i'm not a primitive-style camper so i've never depended on a fire as my only/main source of warmth...are you done trying to derail this thread?
I can describe 2 scenarios where I carry an Emberlit as a source of warmth.
The first is on remote long distance XC ski tours. The stupid danger of XC skiing (like mountain biking) is that you can easily get deep in the woods quickly provided you have a light pack. And as one learns to ski faster with a light pack, one aspires to attempting longer routes as day trips or long day trips. These trips are only possible is you eschew full over night gear like a pad, sleeping bag and tent. The are the XC equivalent to a alpine style climb and as Chouinard noted, "If you bring bivi gear, you will use" (because the weight will slow you down). These trips are built on Chouinard's credo that "speed is safety". But, obviously, things can and sometimes do go horribly wrong. If anything impedes progress, you're screwed. A few years ago, a party from Harvard University attempted a Pemigewasset traverse, foundered in deep, unconsolidated snow, became dehydrated (streams were covered), became benighted and almost succumbed to hypothermia in the long dark night.
Here in New England, such ski routes tend to be in lower hardwoods where small deadfall is plentiful, even in deep snow cover. My emergency provisions for surviving an unplanned night in the woods include insulated parka, insulated pants, 9'x9' tarp and the Emberlit. The tarp can be easily pitched diagonally off of a tree to provide a good wind break for 2 people. The Eberlit can be placed on some sticks on the snow and can be fed for a long time with minimal effort and without the problem of burning down through the snow to ground. It's a perfect, portable way to keep a "scout fire". Can't do this with white gas or liquid fuel. Had the party from Harvard been carrying an Emberlit and a small pot, they could have easily melted snow for water and avoided dehydration.
Second time I carry the Emberlit is for group trips above treeline. I recently took a Wilderness First Aid course and the instructor recounted a rescue in NH from this year where a hiker broke an ankle near tree line and their partners kept them warm using a small fire. Getting an injured hiker down from above treeline is always a good thing due to the increased risk of exposure but there is very little useable wood in the stunted "krumholtz" zone of fir and spruce. Again, the Emberlit would be an ideal way to sustain an emergency scout fire in that situation and it's now found a semi-permenant place in my emergency kit for this reason. Top tip, it packs well next to my SAM splint.
For more mundane overnight camping, I've found the large Emberlit makes a decent, if fiddly, windscreen for a sit-on-top type alcohol stove. I've moved to alcohol stoves like the Batchstovez 2.0 for my 3 season camping. I also use a GSI soloist for 1-2 person groups. Just the perfect size and a good match for the Batchstovez. The Emberlit assembled as a 5 panel manner with the floor acting as the 5th panel makes a perfect cone shaped windscreen for this type of kit. The indestructible Stanely pot also works like this.
Untitled by
Pinnah, on Flickr
I strongly prefer to cook over alcohol. It's just so much easier. But, stuff happens. I was just on a trip where my partner's canister stove failed (I hate those things) leaving my white gas Svea as the only stove for a 4 day trip. I hadn't planned on being the sole stove so cut the white gas too thin to cover us for the full time. Having the Emberlit in my emergency kit allowed us to use the white gas when at treeline knowing that we would have wood fuel in abundance when we got down to lower elevations. I was able to bum some gas off of another hiker, but the point remains that a dual fuel sourced kit adds a great deal of flexibility to the kit.