Do gods in 5e still have a "portfolio"?

Question

Having studied the sources available to me on the 5th edition, I did not find any mention of the portfolio. We only know that now all the gods except Ao and demigods are inferior gods and nothing is said about their level of power in relation to each other.

For example, we have Auril from the adventure of Icewind Dale: Rime of the Frostmaiden, where we are given the opportunity to supposedly kill a god, but it is impossible to take her sphere as mentioned in the sources of earlier editions.

In general, I want to clarify the situation about the portfolio, whether there are any and how to get them if so. I am only interested in the information valid at the time of the 5th edition, that is, after 1498.

Answer 1

Portfolios are still mentioned in the Player's Handbook and Dungeon Master's Guide

The concept of taking a god's portfolio as a mortal has in the past only happened during extraordinary circumstances. Before the timeline of 5th Edition there was the Era of Upheaval, caused by Ao casting down the gods to walk the world in mortal forms in response to the Tablets of Fate being stolen (they were eventually returned but Ao destroyed them). This time is when a lot of gods were killed. This era ended with Ao restoring and rewriting the Tablets of Fate, writing down the names and purposes of all the gods. With this the pantheon of gods appears rather set in stone as long as they gain worship.

I do not know of any instances of a god's portfolio being taken by a mortal during the timeline of 5th edition. If you are a DM you are of course free to introduce similar cosmic events or perhaps forgotten rituals that would allow your player's to ascend. If you are a player, all I can say is ask your DM.

This section is specifically about the adventure Rime of the Frostmaiden since you mentioned it in your question. If you are not a DM do not read this, it is a spoiler and you should ask your DM about this.

The adventure is set around the premise of Auril casting some sort of divine spell around Icewind Dale and the adventure explains that "each casting of the spell leaves the Frostmaiden weakened, with just enough divine power left to barricade the mountain pass with blizzards and churn the Sea of Moving Ice with blistering winds". Auril is thus set up as being drained of most of her divine powers and the adventure provides stat blocks with the intend of your players fighting and possibly defeating her. However, Auril is not mortal as described in the Epilogue: Auril’s death is temporary, for a god who has mortal worshipers can’t truly die. When the Frostmaiden is resurrected on the next winter solstice, she has all her divine power.

Answer 2

Portfolios still exist

A portfolio is a kind of "theme" that the god is responsible for. It was a bigger thing in earlier editions, but there is some support from published 5e sources that the concept still exists. Sword Coast Adventurer's Guide, page 30:

Jergal calmly abdicated his throne of bones and allowed each of the three mortals to take part of his divinity. Thus it was that Bane assumed the portfolio of strife, Myrkul the rulership of the dead, and Bhaal the portfolio of murder. Jergal lost his former stature and became a scribe of the dead.

That the players are not offered to take over Auril's in Icewind Dale: Rime of the Frost Maiden is to be expected, because (p. 261, "Epilogue"):

Auril's death is temporary, for a god who has mortal worshipers can't truely die. When the Frostmaiden is resurrected on the next winter solstice, she has all her divine power.