IIRC Bertie was distantly in line for a baroncy anyway, so the House of Lords was more or less inevitable.
I also think that he'd have been quite a decent cove in that situation, he certainly didn't approve of unfairness, and had no time for bullies so would have regarded that nasty Mr Hitler in the same light.
Plus, considering the shower we currently have in post, at least we know Bertie was never particularly dishonest. And with Jeeves at his side, it'll be like "Yes, Minister" with Hacker and a slightly more supportive Sir Humphrey.