4 billion years ago, Mars and Venus were once habitable. Venus became too hot due to the sun's growing hotness and Mars grew cold due to volcanism lost. Venus probably once supported complex life until it went into a green house planet. The Earth will share a similar fate in the future.
Mars lost its oceans at some point but in 2 billion years, the Earth would have looked similar to Venus then. The habitable zone shifts over and the ice on Mars melts thickening the atmosphere creating a green house effect and Mars will once again have oceans on its surface. Life in the poles could migrate to colonize the new Martian oceans and then eventually,land. However, Mars will not last forever, eventually, Mars will be a Venus like planet and no longer be Earth like again.
5 billion years from now, Sol has now consumed the inner solar system. The Jovian moons become habitable. Ganymede's ice melts, some thickens the atmosphere the other becomes a liquid state. Callisto will melt to have continents and oceans and Europa will have an endless ocean. Io might either stay unhabitable or will have oceans with highly volcanic lands similar to when Mars was young.
7 billion years from now, Titan's rock solid water ice is now at liquid state. Temperatures will first be -60 degrees C but the ammonia being pumped from the volcanoes will heat up the planet even more until Titan has oceans. By now, the methane would have completly boiled away.
If the descendents of humanity use up all of the resources, the Uranus is reduced to a dead barren core slightly bigger than Earth and over the billions of years, coments delivering water and organic compounds did a kickstart to the planet. By now, the planet might have continents and oceans.
The descendents of humanity might do the same thing to Neptune as they did to Uranus. And Neptune's core which is bigger than the Earth will go by a similar process to Uranus's core.