I have been using similar bottles, from the pound shop. Cheap enough to not worry about hacking them about.
I have cut one down to fit inside my titanium mug, with a hobo stove and trivet.
But I found that the threaded ring that was crimped into the neck, for the cap to screw into, were not tight enough to seal. Also the seals would expand with meths. So have sealed the cap ring with silicon RTV rubber, and replaced the seal with a Buta-nitrile one. And the seam, where I cut the bottle down, is done with silicon.
The seem seems (!) to be holding up. But that was a press fit.
The recently sealed cap, ok so far.