Ragnarok

So we’re playing in the forgotten realms and I have an idea to have my players slip through dimensions and land in the 9 realms from Norse mythology shortly before the time of Ragnarok. I plan to take them through a few of the realms gathering allies for the main quest too and weapons. I am just a little worried this will take quite a long time away from
The direct world of the main campaign and was wondering if anyone has tips or think it’s a bad idea out right.