How would you imagine the size of the universe will change in the future?

According to the first law of thermodynamics, the universe will continue to expand as long as its rate of expansion increases. The amount of matter and energy in the universe will remain constant, and the same amount of matter dispersed over an expanding and potentially infinite amount of space will become increasingly diffuse.

The second law of thermodynamics states that as matter spreads, it will be converted to energy, which will then decrease in level and organization. As a result, there will be no matter left in the universe, and the energy will reach a point where the universe's temperature approaches absolute zero, leaving no useful energy or matter remaining. This eventuality is known as the "heat death of the universe."

There won't be anything left that is visible or useful when the universe reaches its limit due to its expanding size.

The size of the universe is unlikely to change in the future. The expansion of the universe is currently ongoing, but it doesn't affect the size of individual objects or systems within it.