Well, I know you exaggerate for emphasis, Leo.
Maybe refer to
this post in the japanese maple chill hour requirements thread,
@LeoCosta
I am not exaggerating, I did abbreviate my answer, in which I did not include all the "pre-conditions". As you know I am a "blueberry farmer", and read the commercial fruit production literature. In Michigan, there was a catastrophic thaw freeze episode in February of 2013. In Michigan, zone 6a, normal winter lows run between -10 to -15 F. (-23 C to -26 C ) and for the fruit trees normally grown in SW Michigan, these temperatures are no problem. However, in February, there was an unusually strong, and lengthy "late winter thaw" in which for 72 hours the low temp was above 45 F, above +6 C, with daytime highs of 80 F. Then rapidly the temperature dropped back to "normal" with night time low of 0 F (-18 C ). The result was near total freeze kill of flower buds for apple, peach, blueberry, cherry, apricot, grape and other fruit. The 2013 crop loss was near 100 million dollars. Catastrophic for Michigan farmers. Now zero F (-18 C) is well within the normal freeze tolerance of commercial fruit grown in the area. The end analysis was that the warm spell had reversed the process of cold adaptation. The trees had begun the process of "waking up", and had begun to increase the water content of tissues, increase the water content of sap, and other changes that are harbingers of spring growth, and work counter to being adapted to cold.
Some of the changes trees undergo to adapt to cold include change the water content of tissues, effectively making them more cold resistant (anti-freeze like) by lowering the amount of water in tissues and sap. This process takes at least 2 or more months of decreasing night temperatures in autumn. When a tree wakes up in spring, it changes the water balance back to a higher water content, so sap will flow easier, and metabolism can increase in rate.
It turns out, especially after the minimum chill requirements are met, the metabolic changes made to adapt to extreme cold can be reversed fairly quickly.
Conclusion - if you live in a COLD climate, bringing a tree indoors will rapidly undo adaptations to cold. If your winter is normally 0 F (or -18 C ) at night, bringing a tree indoors for 2 or 3 days can "wake a tree up" enough that returning the tree to 0F ( - 18 C) at night could be lethal.
Obviously, if one has a winter storage area where temperatures are mild, or an area where temperatures are controlled to be above freezing, but below 40 F (+4 C ), then the issue of bringing indoors for a few days is moot.
I'm in a cold winter area, and winter the majority of my bonsai outside, on the ground, with no protection from temperature. Just a little wind protection. Knowing the above, I don't bring those trees indoors for more than a brief few hours. The trees I store in my well house, where temperature always stays above freezing, I can bring those in for a day or two, and they are fine.
Note, some trees, like Japanese maples will "wake up" rapidly, 2 days indoors might be fine, but 5 days may very well start the spring growth cycle. Once they start growing, returning them to cool, 32 F to 40 F storage will not stop the spring growth. They will keep growing.