I have not tried this (not having gotten past the first plot) so I can't be sure of how this exactly works.
But!
The prestige difference will be returned to the SG, much like selling a room.
If I were you, I would design the base according to the smallest plot specs. That way, you 'should' have the minimal fuzz and least chance of things going bonkers.
@ShadowGhost & @Ghostie
The Grav Mistress, Mistress of Gravity
If you have nothing useful to say, you have two choices: Say something useless or stay quiet.
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Would i have to first rearrange the rooms so that they fit in the smallest sized grid or will i get the opportunity to move the rooms around to shoehorn them in afterwards?
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If you want to down size the plot you will have to arrange them to fit on the smaller plot before it will actually let you make the change.
Theres no opertunity to do anything on the plot upgrade screen other than a plot up or down grade....oddly enough 
I'd advise you to sell off some of the rooms and standard items, then move all your personal items into one or two rooms (depending on size).
Downsize the plot and recreate the base, then moving the personal items back again. If you sell a room with a personal item still in it, you lose it and only get the prestige cost of placing it back! So be very careful.
I suggest trying it on the test server first. I think they still give new SGs there a huge prestige boost
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I suggest trying it on the test server first. I think they still give new SGs there a huge prestige boost
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I dont think they do anymore.
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I'd advise you to sell off some of the rooms and standard items, then move all your personal items into one or two rooms (depending on size).
Downsize the plot and recreate the base, then moving the personal items back again. If you sell a room with a personal item still in it, you lose it and only get the prestige cost of placing it back! So be very careful.
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yep this is exactly what i had to do with the iron monkey base on revamp - effectively it was reducing it down to 1 workshop or a room capable of taking the storage items and then a miriad of tp rooms all over.
took a fair while of shuffling things round and trying new shapes to get things to fit - i used the 'upgrade plot' window quite a lot just to move the plot around rather than resize - to aid in deleting and rebuilding rooms.
its the reason the base changed so radically as all of those little cool design points on the wall all had to be ripped out to allow the base to be swapped about.
sometimes a bit tedious but i looked at it as a logic puzzle, 3d tetris 
but becuase its such a destructive procedure it does make the base very static once you've min/maxed the plot size and put the design features back in.
@ExtraGonk
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took a fair while of shuffling things round and trying new shapes to get things to fit - i used the 'upgrade plot' window quite a lot just to move the plot around rather than resize
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Thats a very good tip especially if you are trying to re position the hidden entrance room on your plot.
If i have a base with a myriad of rooms already set up and running and then in order to take advantage of the lack of rent on the smallest plot size i wanted to downgrade but wanted to keep all the crafted kit in there can i do such a thing?
Would i have to first rearrange the rooms so that they fit in the smallest sized grid or will i get the opportunity to move the rooms around to shoehorn them in afterwards?
Edit: Also, would i get the prestige spent upgrading refunded back into the SG?
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