The bolded text isn't true. Continents are easily plastic enough to deform under the weight of 2 miles of ice and don't rely on "memory" to return to a previous shape after the ice melts. Even if they weren't plastic, continents maintain their elevations because they are lighter than surrounding magma and heavier materials that form sea beds.
If the continents didn't deform when the weight of ice was lifted from them they would simply rise as a single plate due to the release of pressure on their surface.
But the rest of what you posted is true. Glaciation is a cycle that has been advancing and retreating for 4 million years, before that year round ice was usually non existent even at extreme latitudes and high elevations.
There is no reason to fear a world with no ice caps, no glaciers and no entire continents covered with ice.
There is a reason to fear all of Russia, Canada, Greenland and Antarctica as well as 1/3 the US being shrouded under miles of ice while sea levels drop a few hundred feet.
Take a geology class then get back to us.
Thanks for acknowledging that you were wrong.
I hate to tell you mate, but that type of response just makes you look foolish. I was serious about taking a geology class, start with Historical Geology and your whole view of the world and how it functions will change.
For a continent to deform there must be a source of energy to do so. There are several that will cause land to rise, orogenies is the most common, but isostatic rebound only occurs when a great weight is lifted from the land or as a byproduct of an asteroid strike. There are no astroblemes in the Great Lakes region that I know of so that leaves a continental ice sheet as the cause. This is a simple fact. Look it up.