Ragnarok could happen, have happened, etc. I tend to stick with the viewpoint that time is different for them. Regardless, as an addition to what was previously said on the matter- a lot of Heathens, etc, work with an aspect of Loki sometimes instead of him as a whole. You could work with him from various different points in his life, thus, I would assume you could avoid the whole Ragnarok debate entirely.
If you want more opinions on it, I would ask Heathens (mainly Rokkatru followers or Lokeans) rather than those who practice Northern Tradition Shamanism- because NTS does deal with some of he deities, but that isn't the primary focus of the practice. Heathens or even seidhr-workers would have more UPG/PCPG to give to you. Most of the work I've read on the matter coming from Raven K (since you put this under the context of NTS) suggests that he can really be found anywhere. He doesn't have one specific place known to him where he stays.