I'm also having the same problem! A sigma agent advised I could replace liberase TL which I use now, for Liberase TH but I think that also had a bit of a backorder. A colleague of mine tried collagenase on pancreatic tissue but don't think he had much success with that. If anyone has a protocol that works particularly well on lung tissue I'd love to hear it. 

Depending on what your populations of interest are, mechanical dissociation might be good, but it won't yield particularly high numbers of DCs as they need enzymatic digestion to properly dissociate from tissue.