tp: not clear what you are exploring here. The precise answer to your Q is: none. Churchill's take in his work of fiction which won the Nobel was to look to the bright star in the West, so UK to do what it takes to bring US in, not as arsenal of democracy, but as soldiers thereof.
Drawing breath with relief, 9-11/40 after our near-run thing, Minister of A/c Production Beaverbrook assigned industry resources to produce kit for the Spring 1941 renewal of German/Italian attacks on us, world wide. The Heavy Bomber Production Groups were launched, briefly including the Supermarine one, bombed out late-Sept. The only course we felt we could follow was to add aerial blockade to the Brit. tradition of Naval weapons of mass destruction upon the littoral civil population. Anything but full frontal attrition.
If...FDR had dismissed our assertions that we were broke, had demanded cash to continue, no Lend Lease, and :
If...Musso had not bounced Germany to turn South before East, 4/41, and/or:
If...Germany had chosen to brush UK away 3/41 before heading East in, say, July,41...then...this board would be in another language.
UK had no workable options, 9/40, except to try to survive awhile till something turned up. Or to ask nicely whether the Offer was still open, that he has the Eurasian Land Mass for Lebensraum and we have the sea.