How tall are you? Tyrell's models are designed for Japanese riders, so have handlebars positioned closer to the seat and a fairly short maximum saddle to pedal length compared with other brands. The Ive is probably the smallest of all Tyrell's models. I'm 183cm and even with the longest available (non-standard) seat post installed, the saddle to pedal length is still about 4cm too short (and about 8cm too short with the standard seat post) for me. I confirmed this at a Tyrell dealer in Tokyo. I also contacted Tyrell asking about custom options for more height and they said they offer none.

Regarding the Birdy, I don't see many with adjustable handleposts in Japan. Most seem to have shortish non-adjustable handleposts to suit the local market and replacement handleposts are expensive. But its a German design so is probably a better than the Ive if you're tall.

I have a Tern X11, which I believe has the same frame as the P10. Its a great bike and I've had zero problems with it. For more handlebar height, I swapped out the 290mm handlepost for a 350mm handlepost (purchased through the Tern online store based in Taiwan - wasn't cheap, but wasn't Birdy expensive either). Its also possible to adjust the Syntace stem to move the handlebar forward or backward to match your desired position. I'd steer clear of any electric motor Terns, but the P10 will be fine.

Edit: The Tern P10 (and I assume the other two options as well) can be disassembled and placed in a suitcase to be checked-in when flying. Tern offers the following kit for doing that. They also offer a suitcase but its available only at dealers, not online.

https://buy.ternbicycles.com/collect...cts/flightsuit