Clematis pruning

[Palustris]

I have spent much of the day pruning the Clematis viticella types. Doesn't it seem a shame to cut them down to 30 cms (or even to ground level as recommended by some experts)?
Yes, I know, they flower better on new wood. BUT here is a part of the problem, what does one do with the pruned off bits? My Angel alone has produced a mass of wire about 4 cubic metres of it!  Add to that the top growth from C. campaniflora which is even bigger and the 18 plants on the Pergola and you can imagine the size of the probelm. It will not shred (it just gets tangled up in the blade of the shredder and wraps itself around.) It will not compost. (Not quickly anyway). Burn it?, yes well, guess who forgot to leave anywhere safe to burn things. :-[
And then of course there are the rose prunings.

[Palustris]

[Hex]

We are lucky in that we have a second wheelie bin that is a green waste collection once a fortnight that drives what pruning I do when.
We have two ivy covered outbuildings which I havent really trimmed in the last three years.  Now seriously overgrown and needs cutting back asap so we can get past.  How much can I take off in one go and when?  It is a foot thick in places.

[Palustris]

February to March and as hard as you like, back to the stems which are clinging to the walls. The Parsley leafed Ivy up the wall of the Hidden Garden was chopped back when we put up the new Greenhouse to within an inch of the wall and it is now almost back to its original size.
The bin is full of rose prunings already and this is the back of beyond, you know!

[Palustris]

More rose pruning this morning, Mermaid climber. Now we have a pile of rose stuff and the bin is full. Have you ever tried shredding rose stems? Remind me again why idiots grow roses? Before you answer, the pruning was to get back to the rootstock so I could dig it out and replace them with something I like.