it is a bit time wasting activity to seek other habitable planets with an idea to go to live there. all of them are so far away that the conditions of the planets we see today, by the light that has arrived to us, may not represent the current conditions. if to count also the time which takes to travel there then those who arrive may find out that by this time the conditions of living there have become worse than on the planet we’ve got right now for living. all that technological effort may be better spent for taking care of this planet here, and protecting it from dangers of destruction by objects from outer space, till we become capable of space travel at will.
this doesn’t mean that we shouldn’t create living possibilities in outer space right now, in order to survive as a species. this is a must. but to colonize other planets, even in our own solar system, is not the smartest way of spending resources. if we find out that there’s a cosmic destruction waiting for a planet, let say mars which has been inhabited by this time, then you can’t move the doomed planet to another location which would be safer. in my opinion the only way to secure the survival of our species is to create movable colonies in space, several of which better be in relatively close proximity — if one will fail then inhabitants can rapidly move over to other ones nearby.
far away inhabitable planets could be a possible stopover, if confirmed safe while being nearby, when the moving colonies have spread out far enough naturally, but definitely not as a goal which requires enormous resources. necessary raw materials for colonies in space are easier to get from nearby flying space rocks, than from far away planets which by the time of arrival there may become impossible to approach due to some natural disaster, or discovered to be inhabited underground by other organisms who wouldn’t welcome us.
seeking other inhabitable planets would rather be useful to map out the locations in space where better not to go, not to interfere with some possibly hostile living forms, but not with the idea in mind to go to live there.
as our technology is not there yet to protect us from cosmic radiation out of the protective magnetic field of earth, it will be smart to build a permanent movable colonies on low earth orbit. the construction must be such that if the protective materials become available in future, then it will be possible to cover the space colony with a radiation repelling layer, in order to move further in space. the inhabitable colonies must become completely self-sustained in some point of the construction, including the technology to gather materials from space for fuel, and construction of space ships, all that without relying on support from earth. without that capacity the whole survival of the colony is impossible in long term, if it needs to move farther away from earth in case of a global disaster.
regardless of the widely known fairy tale of already achieved visiting of the moon by humans, it is still not in the technological capacity of mankind to protect us from cosmic radiation. if we don’t wish to remain stuck on earth forever, waiting for inevitable next mass extinction by a space rock, then there are two most important goals to achieve: one goal is to engineer humans to be capable of genetically self-repairing the damage done by radiation, and the another goal is to create radiation repelling materials. whichever is achieved will set the stage for possible space travel away from earth, but before that nothing will be able to save us, even the most advanced rocket technology to move around at will. so far we can only send robotic probes to outer space, but not to go ourselves.
in any case, the seeking of habitable exoplanets should be not for the goal to go there or even to poke them with any technology, but rather to map out the areas to avoid, just in case.