I don’t see how the UK could hold Africa without US help and Russia shure can’t afford to help. I think the best you could hope to do is slow them down.
I played one game that the Axis could not get into Africa just because the dice went so bad that the UK held them off in Egypt, but that was some monster bad luck (or good depending on the side you happened to be playing on) that made that happen, nothing more.
You might be able to slow the Axis down in Africa by spreading your units out and making them fight for every territory, but like you said, they are probably dead before you even get a chance to use them.
A factory in the bottom of Africa might help, but that’s another BIG might.
You could try chasing them into Africa from the Atlantic; taking the land they just took from you, but that would take a lot of effort, reducing any of your efforts into Norway to virtually nothing.
With out US help…I’m out of ideas. LOL…I guess?