Geosynchronous satellites are only 23,000 miles up. The ISS is really close, 200 miles. For contrast, Pluto is 4.7 billion miles distant. New Horizons (pluto probe) power output is 12W per TWTA (the amps that power the antennas). The signal received here is low, to be charitable. Both the mobile (probe) and fixed (earth) antennas are directional, and the data rate is low, but the signal reliably goes both ways.
Can a wifi signal get to 23,000 miles? Yes. Is current tech able to see it? Not at wifi state of the art in antennas in stuff you can buy at Office Depot.
Can you see a 70 mW beacon (constant transmission) at 23,000 miles). Technically, yes. Especially if you know where to look. Noise averages to zero if you observe long enough. Signal sticks out of the noise when noise = 0. Digital signal processing techniques provide something called processing gain that does exactly that.
Modulate it with data and all you do is stretch out the time required to detect a bit.
The normal way of calculating signal strength reductions assumes an antenna that radiates in a sphere. Making the transmitting and receiving antennas directional puts the power in a narrower beam, but it spreads out over distance, regardless and some energy gets absorbed/reflected by intervening obstacles. The New Horizons dish antenna is only about 3 feet in diameter and it gets 12Watts here from 5 billion miles. We have antenna arrays here which make the receiving antennas HUGE, and DSP to recover the signal, and badass amplifiers and we know where the signal is, which helps.
Anyway... we can detect neutrinos and cosmic rays and single photons. Enough money, tech and time in the detector and you can do a lot. Ham radio folks doing low power routinely communicate worldwide on a watt, using their EARS as detectors (along with the radio hardware, of course.) Your eyes can detect galaxies against the black background of space. The distances involved are unimaginable.
Again... if your question is "Is there a physics reason why you can't?" the answer is a no. If it is "Can off the shelf wifi hardware/software do it?", the answer is still no. Engineering is always having to grapple with economics, but absent economic constraints, the sky's the limit. Kinda.
I'm thin on numbers here, I know. But I have to go now. Hopefully someone else will pick up.