A very Happy New Year to all forum users and moderators!

After a (very) long pause to my printing sessions, I came back to print a tunnel portal for my train model layout.
As I watched my design come to life, the question just hit me:
Do we need to keep the heated bed ON throughout the print?
I mean, the heated bed has a very specific purpose: to keep the first layer(s) of the filament in such a state that they stick well to the build plate so that as printing progresses, everything stays in place and you get a solid object in the end.
However, as the print head moves a way from the first layers, do we still need to keep the heating on? Will the part(s) run the risk of getting detached from the printing surface?
If this is not the case, it would be interesting to add a few lines of G-code to gradually reduce the temperature of the heating bed to a full shutdown thus preserving electronics and saving a few watts during printing...

I would be more than grateful if anyone of the experts out there could answer this (possibly silly) question....

Many thanks in advance,

Nikolas

P.S. I am using a Wanhao di3 v.2 with no mods and am printing mostly in PLA