Test it and see. Make a 2k map with a 1-pixel checker. Export the model to Marmoset. Position the camera where you want your end shots to be. See if the texels are larger than the screen pixels. Usually you can get away with significantly larger texels. You just don't want a single texel to take up more than, maybe, 16…
Next gen does not equal giant textures for everything. In a real-time rendered game, all the same old rules still apply. Use textures no larger than necessary. In a real game situation, you will almost never see a 4096 texture on a single asset. This is a portfolio piece though, so you can be a bit looser with memory…