Having lived through several Hurricanes here in Florida I can best describe them as a night of terror followed by absolute boredom.
For some reason all the ones who came through my area ( Northeast Florida ) have occurred at night.
There is of course a concern for tornadoes but the greater danger is the winds causing the trees to weaken and come down or else a big tree limb to come down.
I got to experience the " crash and boom " effect. The crash is a tree or tree limb coming down and landing on a power line and the boom is the sound of an electrical transformer exploding. All night long you got to hear this effect spaced about 10 minutes or so apart.
People who get killed usually get killed by a tree coming through their roof or a tree coming down on them when they are trying to drive somewhere.
After the storm the power is off and you may well be blocked in by downed power lines or big trees blocking the roads. Generally then for most people comes the real boredom of having no power and not being able to get out and go anywhere.
Unless you work in some capacity in emergency services you really just have to sit around and wait for help from the outside to arrive, even if you do work in emergency services you may find yourself blocked in as well.
Power will be restored to hospitals, supermarkets, stores, and fast food joints first generally in that order. Individual residences will be restored last starting in urban / suburban areas first and rural areas last.
The power companies will do their best to restore your power as soon as possible, it's in their interest because the longer you go without power the more you learn to live without it.
Hurricane Irma was the most damaging, there were a lot of damaged roofs in my area ( including my own ) and the supermarkets due to damage to the ports had about two thirds to maybe half of what they normally carried.
It took about three weeks to a month for the stores to become fully stocked again. Nobody starved or anything like that, but you couldn't help but be a bit pissed that your favorite items might not be quite so available.
If the U.K. crashes out and things go really south, then while there may be some things it can do to help itself, it may well for the most part have to wait for help from the outside to right itself.
I'm not quite sure how applicable a post-hurricane recovery situation would be to the U.K. post March 29th.
I will say though that while governments can get bogged down in details over policies at times, in an emergency they can be surprisingly quick to respond.
A plausible scenario might be then that a no-deal crash out would be intense but the intensity would be fairly short lived as the government enacts emergency measures to try to correct the damage.
There would of course be lasting damage to the U.K. but it most likely would not be a permanent dystopian nightmare but rather a much diminished place from what it was.