I'd like to leave around 12, but if that's too early, we can leave after 1:00.
It would be good if we could take off around noon, but if that doesn't work for you, anytime after 1:00 is fine too.
この場合、次のような言い方ができますよ。
ーI'd like to leave around 12, but if that's too early, we can leave after 1:00.
「12時頃に出たいけど、早すぎたら1時以降に出ることもできるよ」
to leave で「出発する」
ーIt would be good if we could take off around noon, but if that doesn't work for you, anytime after 1:00 is fine too.
「12時ごろ出発できたらいいけど、都合が悪かったら1時以降でもいいよ」
to take off で「出発する」
anytime after 1:00「1時以降いつでも」
ご参考まで!