I take evening walk for about 50 minutes everyday and have same requirement as yours. I have multiple walk lights and none will meet the 1000 lm sustained brightness, except one, Wurkkos TS30S with SBT90.2.
It’s my most favorite walk light and is pocketable both in jacket and my loose khaki pants. Slightly large but IMHO this is the minimum size for your requirement if you want “best” possible light. It’s a well known light; google it for uniformly great reviews. I also have my impression here: Wurkkos TS30S + monster LED SBT90.2 = $60 4750lm 1km SUPER-Thrower. Comparison w/ TS30S Pro, Olight, Nitecore, & other monster lights. :)
TS30S stays very bright and has a balanced beam: tremendous 1km throw with a very good spill for close range. Max output is 4000 plus - a true pocket monster. Above all, frequently on sale for $60; an absolute steal. When I have time I should check myself to make sure :) but below is runtime in excellent review by Luxwad seems to meet 1000 lumen x 1 hour requirement:
