It's a great idea, you should seriously consider it if you have a party in your novel.
There are two approaches. One is to peel off characters one by one to deal with problems that could stop the final climatic success, while the others go on. This concentrates focus on the main character. The other is send characters in different directions to deal with different aspects and keep shifting points of view between them.
Both can be unwieldy if the group is too large. Even the first may require more peeling if large chunks can not be split off. The second may split the story so much that it turns from a river into a marsh. Still, nothing allows characters more chances to shine that being alone, even if it's being alone at the portal on Earth and defending it from all attackers so that the main party can return.
And while you have to make them all interesting, the reading audience is more likely to be interested in four characters than three players are to be in the fate of another's while their own characters hang in abeyance.