Unfortunately the way we all get cheap or free next day delivery is through drivers having lots of drop-offs and no turn around time. And they don't take into account disabilities, should do but then Amazon also forces drivers into pissing in bottles so even where it's the law it would still be something you can't rely on.
Might be worth looking for a tech solution Kaz, if you can track when it is being delivered you can have a garden trolley out ready for them to put it in. Not sure if there is a step to your door if you have side access, but would that work for you?
You'll need to get someone to lift it and assemble it for you though.
I have a video doorbell that also starts recording and sends a notification to my phone when movement is detected, shortly after installing this the postman delivered a signed item worth over £400 to next door and the arseholes left it outside after signing for it. I'd rather things go back to the depot than have to rearrange delivery than shitheads do stuff like that.