Help my chickens survive lockdown

Here in the UK, all captive birds are legally required to be under cover because of avian influenza.  This happened last winter too for a total of six months, a long and miserable six months.  

I have five chickens and three ducks, and they're locked up in a small coop (a converted wooden playhouse) with a very small covered "porch" for them to step outside for a breath of air (it's a patio table covered in rabbit wire).  They are friends with each other, but living in extremely close quarters and not really able to fulfil all their basic instincts;  for instance the ducks have no access to their little pond, but just a bucket to dunk their heads in.  Under normal conditions, they have their own respective yards and are allowed a certain amount of free ranging around our small property.

They are all miserable, and I am miserable for doing it to them.  How can I improve their situation without breaking the law--and also without breaking the bank?  They are allowed to be outside if wild birds are completely excluded, hence their porch.  I have some access to a few cast off materials, such as a couple of pallets, a bit of chicken wire, various odds and ends.  I also have a little A-frame moveable tractor which I let them live in last spring after it warmed up a bit;  it has no floor and is about a quarter of the size of their coop, but I figured it was better to get fresh ground every day--with something fresh to peck--than to be locked up in six months of poo.  I can't really let them live in it in the middle of winter, though.

I will take any suggestions with thanks.

Could you let them out 45 minutes before they go to bed and stand guard to chase away wild birds?  Likely not as I'm guessing it's their droppings that are the problem...

Would you be able to use the materials you have to build tunnels leading out from their coop/porch? That way they would be able to wander and explore some new area, but you wouldn’t be using your materials to build unnecessarily large structures. And the tunnels might be able to be moved regularly.

I have a shelter with some older ducks and chickens that is secure from coons, but no fun for birds 24/7. It's not a size issue, but a boredom one. I have trained this group to go out to a portable Dog X-pen run for the day, and then run home at night. I give them soaked wheat in the run which both species adore, and limited the food during the afternoon while I was training them for the "bedtime" run. Being a little hungry and knowing there was some chicken feed in their house helped teach them.  I try to only move the run "one square" east/west/north/south, so they don't have to wander looking for it. I mark the entrance with a pair of white buckets to help also.

So the question you'd have to ask the powers that be, is would they be allowed to run independently under supervision from your hutch to the A-frame and back again without breaking the rules?

I do use a hockey stick and practice my stick-handling skills to guide anyone who gets lost. Many days they do it perfectly... occasionally they're total bird-brains! The hockey stick really is just an extension of my arm down to their level, but it's amazing how effective it is. My friend who has bantam chickens was so impressed she got herself one at a thrift shop. We both use "child-sized" ones as they're more convenient.

Fencing is really expensive, and needs to be decent quality to exclude predators and wild birds. We've had coons rip right through chicken wire, and they will tag team birds to get them close to an edge. Keeping portable shelters light enough for one person to move is a big issue. It's not very permie, but I have 4x8' mini-PVC hoop houses that I use for Momma Ducks with ducklings that are 2"PVC rectangle as a base and 1/2" pvc hoops over the top with a mixture of tarps and hardware cloth. They are incredibly easy to move. There are lots of designs on the web, but you'd have to decide if the cost/benefits work for you.

Do you have something like Freecycle in your area where you could post asking for more materials like chicken wire and pallets or fencing, etc.? I raised a family of 12 ducks and their mama using an enclosure like this https://www.amazon.com/Trixie-Products-Natura-Outdoor-Cover/dp/B000V6C7DQ/ and I made a pond for them  with a stock tank (that I now use for many other garden-related stuff like collecting compost tea under my composter) like this https://www.tractorsupply.com/tsc/product/tuff-stuff-products-heavy-duty-oval-stock-tank-15-gal. Every day I'd open the top, step in, and lift it a bit and move it to a new spot. Wasn't ideal, but kept them safe. If you did that with a few of the adult-sized ones and let them all have some time on the grass or in a "pond" maybe they would be a little happier.