See, I've always known that Scandinavians must be crazy but you, Sir, have taken it to the next level! Congratulations on achieving something absolutely remarkable. I did ride my bike at -12°C but only around town - short distance, low speed. Cannot possibly imagine to do that on ice for 24h straight.
"Life is not a journey to the grave with the intention of arriving safely in one pretty and well preserved piece, but to skid across the line broadside, thoroughly used up, worn out, leaking oil, shouting GERONIMO!"
You can probably compare that to full Triathlon performance were you are burning more energy on cold climate than you have time to eat and drink.
So I lost 3 kg / 24 h so if somebody want burn fat that will do it.
You also need to have experience of riding on snow and icy grounds with stud tires. There was only 8 hour day light onroute so riding in dark only view of your own driving lights beam and possible reindeer's on the road shoulder what you can't see gives you an extra spice for riding.
Okay we had put the limit there it's your turn to rewrite the record. 1000 miles less than 24 hour coldest time of the year in Finland crossing Arctic Circle north and south bound onroute on different points and survive.
This will change you. Nothing will ever again be black-and-white.
Life isn't about how to survive the storm...But how to dance in the rain!