RTX 2070 with no spec changes on 7nm would be 85w - 7nm offers 50% lower power draw
The current Turing cards done on 7nm you'd be able to put a full size desktop RTX 2080 into those thin laptops and possibly beat a Radeon 7 desktop card lol
If all the power came from the die, still no, because I/O on the die still isn't scaling as well. The memory which is a significant chunk of power and the high bandwidth requirements means a lot of I/O power going off die still. Neither of those scale, one at all and one not well below 14nm just because the main chip is 7nm.
Put this way, a 150W tdp gpu is likely using anywhere from 80-100W on the actual gpu die. If you manage 50% less power at the same clocks and performance on a die half the size then you reduce that to 40-50W, but still add the 50W for memory, mosfets and a good chunk of I/O power which won't change.
CPUs are different in that the cpu tdp is on package only, it doesn't account for memory or the board power from mosfets/etc.
HBM is a huge power saving, which could mean taking for instance a Vega 64, that memory usage on board actually goes from say 30W to 50-60W for less bandwidth but from gddr6. That would make a much worse difference going from an HBM card to a gddr5/5x/6 card than from a gddr based card to a new card with a 7nm core and the same memory.