It's not clear to me that smaller seats makes gerrymandering harder. If anything, the opposite seems to be true.
On the main point, the Wyoming Rule would be an improvement over what we have now, but a better rule would be something which is proportional directly to the total population of the country. Otherwise we hit a paradox where states which gain population may end up losing seats.
Slower growing states should lose seats if its quite slow, thats why the cube root rule makes the most sense, it prevents a super sized HoR in the thousands of members but slowly expands to the house each decade as long as the US population increases.
