The arctic ice melting entirely doesn't change sea levels since that is already water is solid form sitting on water. Sea ice is not a problem. A huge area of the Arctic ocean ice had melted in 1955 or so, and we didn't see major effects on other parts of earth.
Land ice when it melts, it can cause sea levels to rise but not as much as the fear-mongering global warming people claim. When a huge mass of land ice melts, the weight of that ice is removed from the land and the landmass can buckle upwards with less pressure holding it down. That can create a variety of scenarios which can be theorized somewhat. One can say for eg. The Greenland island, when it loses all its ice, can increase in height overall and create a emptiness of sorts underneath where the excess water can go and occupy that space, and the rest of earth won't feel sea level rising.
The so-called global warming can have more frozen land areas available for human activity. There will be land areas accessible in the northern regions of Russia, Canada, Norway etc., as well as in the Antarctica.
While the above is all possible, what really messes up the sea-level rise scare is the way the locals of Diego Garcia island got evacuated so that the UK and USA now use that area for a huge military base, global warming kind of by-passed them with special permission from those 'special people'. The natives scattered around the neighboring islands/countries are still fighting to get back ownership of their land but they will never get it.
So when you hear these sea-level rise, over-population and other danger events, take it with a grain of salt, (maybe a handful is better). Check the sources of the information you heard, then do some research on your own if possible, or get info from other non-advertised sources, then figure out where the truth stands.
Granted there are some places where sea has moved inward on landmasses and some small islands are affected. Check about the activity in those places – there may be some construction stretching into the sea affecting the natural ocean currents that are disturbed now to encroach in some places while building up beaches in other parts. Or those places got their sand beaches destroyed to create conditions for land sinking lower, and the sea just flowed in with no fault of its own.