If you don't have access to a 100yrd range, then the 50yrd cheat will probably work well enough. However, be sure to chrono your bullets to make sure your muzzle velocity is matching up with the published data, otherwise your hold over won't be right. The best advice I'd give is to sight in at 50yrds, then shoot a couple test groups at 100yrds to confirm.

I honestly don't believe a hunter should only shoot at one distance when preparing for a season anyway. Zero your rifle in for whatever range you like, but take a few test groups at different distances to gauge your own ballistics curve. If I'm hunting an area I know I might be taking shots anywhere out to 300yrds, I'll zero at 150, then shoot test groups at every 50yrds from 50 to 350 (Only have to do this once for a particular recipe), then I build my own ballistics chart. If I'm in the brush and expecting 100yrd or less shots, I'll sight in at 75, then verify by shooting at 50 and 100. I write the table on a small piece of paper and tape it to the left side of my scope sticking out perpendicular so I can see it with my off eye even when I'm over my scope.