following my simplest WAN 2.2 workflow with loras (turbo and NSFW), i did very similar workflow for double length videos. It also works perfectly with 16gb VRAM.
just as previous workflow, this should work on any comfyUI installation.
You will need to download all models, vae, clip and loras yourself unfortunately.
how/why set it up.
first part is set as a normal i2v clip. You want MAXIMUM 5seconds length if you want to change the details between first and last frames. if you go longer, the scene WILL start going back to frame 1.
for the second part it will use last frame as it's first. again, 5s if you want to avoid going back, depends on scene/prompt. 7sec in default settings.
it requires a little luck to get last frame without high movement, or the quality of second clip will drop.
use 4steps for low changes in the background and 6 if quality is a bit low.
have fun.
turbo (lightning) loras are here: https://huggingface.co/lightx2v/Wan2.2-Distill-Loras/tree/main
version might be different when You browse it.