British capital-ship responses to Soviet battlecruisers

If Stalin had obtained his battlecruisers, would Britain have modernized Renown again?

Probably not; a second Vanguard or a postwar Lion-class battleship would be more plausible.

Soviet battlecruisers probably would not have brought another modernization of Renown. A more plausible British response would be a sister for Vanguard or completion of a revised Lion-class battleship. The proposed alternative is a 1944-45 style Lion variant adapted to the postwar requirement. This would invest in a newer heavy-gun hull rather than extend an elderly battlecruiser again.