If somebody is makpid on takanas Ezra and chas vShalom has a mikra should they miss davening if they are not able to go to the mikva and instead daven a tashlumin?
A person that has a mikra and does not have a mikva that he can go to should not miss zman tefilah. The Mishna Berura even says that one should preferably not even miss tefilah with a minyan. (Not everyone agrees with this). If you can’t make it to a mikvah you can pour tisha kavin over yourself by taking a shower. Please see the following post https://dinonline.org/2014/03/16/shower-for-9-kabin/
O:CH 68-1 M:B – 2, Teshuvos Vhanhagos 1-109,