Il Principe (of Beleriand...)

[drigel]

You're not going to be in a good position for active resistance from waaay over there.

Forget Beleriand altogether. Head east of the Blue Mnts and set up an initial residency somewhere between the Blue's and the Misty's. There, you spend a few hundred years, both intercepting / interceding Morgoths agents of influence, and fostering the latecomers. See if you can make a difference in the numbers of men that were wooed and allied into Morgoth's service.

Build up ranks of Avari and humans. Migrate en masse west over the Blue mountains. Claim squatter's rights in Himlad or other East Beleriand tracts. Attack massively at once, blowing it all as soon as possible, before the lies of M start nibbling at the edges of your society. Keep fingers crossed. Buy funeral insurance.