Moving and repurposing conservatory as porch.

Yes, it can be done, although the main challenge is taking the existing conservatory down without damaging any of the frames, roof sections or glass. Being 20-odd years old, there’s also a good chance some of the old gaskets and seals will have perished or become brittle, so some may need replacing when it’s dismantled and reassembled. It’s certainly not impossible though. I’d recommend speaking to a uPVC/conservatory specialist rather than a general builder, as they should have no problem dismantling it, adapting it to the new location and sourcing any replacement parts or seals needed.