From Gylfaginning : " Then Third answered: There will be many good dwelling places after Ragnarok. The best place to be in at that time will be Gimle in heaven. For those who like it, there is plenty of good drink in the hall called Brimir, that is on Okolnir. There is also an excellent hall on Nidafjoll call Sindri it is made of red gold. Good and righteous men will live in these halls.
Gimle is listed several times in both Voluspa, and Gylfaginning, and is always referred to as "The best place to be after Ragnarok.
From Voluspa : " She sees a hall fairer than the sun thatched with gold it stands at Gimle. There shall deserving people dwell to the end of time, and enjoy their happiness.
From Gylfaginning : Then Third said : " His greatest achievement ( Odin ) however, is the making of man, and giving him a soul which will live and never die, although his body may decay to dust, or burn to ashes. All righteous men shall live, and be with him where it is called Gimle, or Vingolf.
Also from Gylfaginning : I know there stands a hall brighter than sunlight, better than gold, In lee of flame, Gimle hosts of the righteous, shall it inherit, live in delight, everlastingly.
Then in Gyfaginning it goes on to talk about other heavens and how they will protect Gimle from the flames of Surt's mighty flaming sword, when the death of the Gods is upon us. High One replies to the question, " What will protect Gimle when Surts fire is burning both heaven and earth." High One: " It is said that there is another heaven to the south of and above this one, and it is called Andlang, and there is yet a third heaven above these ones which is called Vidblain, and we think that this place Gimle is there. At present it is inhabited only by white elves. It does not tell if these lower heavens will be destroyed in protecting Vidblain where Gimle is located, but I assume as much.
Before Ragnarok takes place there is also, of course, Valhalla, the great gleaming hall where all the warriors who die in battle go to. It is here that they feast and drink, and then go out and sharpen their fighting skills by battling each other to the death. They do this in preparation for the final battle " When the wolf breaks free ". The victors of these battles go out to the battlefield and carry their defeated comrades in arms back to the great hall where they are reborn. Every night on the golden benches they re -join, "reconciled" with the other warriors, and feast with great All - father Odin.
It is not just men who have another place to go to , besides Niflheim, before Ragnarok. In Gylfaginning, when speaking of the Goddesses it states : " The fourth is Gefjon, she is a virgin, and women who die unmarried serve her. I guess because of their pure nature, not having married or had children, they are allowed to skip Niflheim, and enjoy the company of the great Goddess Gefjon.
One thing that is not written in the Eddas, but is something I believe very firmly in , ( Call it a UPG if you will ), is that all children who die go to live with Frigga in her dwelling place known as Fensalir. I know that great mother Frigga would never allow sweet innocent children, who died well before their time, to reside in a place like Niflheim, where it is said to be damp and cold. Mother Frigga does, I am sure, wrap them in her loving arms, and sees that no further discomfort is brought upon these unfortunate souls. Niflheim is, however, where we are heading in Part 2.
Go with Odin's wisdom, Freyja's love, and Thor's protection !