I have been in a Halifax cockpit and IIRC it was indeed more spacious than the Lanc. In the latter we didn't even consider the upper escape hatch but might have done had we been inverted.
Didn't consider a main door escape as the obstacle course was quite something. What I did consider was either diving under the instrument panel or simply using the nose hatch.
My main concern with the nose hatch was that of inadvertent opening.