Regarding your question whether you may go to Rathayatra festival, yes, you may go because in your present temple the Deities are not regularly installed. So you can close the temple for a few days keeping in front of the Deities some dried fruits and a tumbler of water. When the Deity is installed it is called niyama seva. That means the routine seva prescribed after installation you cannot stop. But Lord Caitanya Mahaprabhu is very kind to the fallen souls of the Kali Yuga and He is satisfied with chanting of Hare Krsna mantra. And for chanting the Hare Krsna mantra there is no hard and fast rules and regulations, so if you are absent for chanting Hare Krsna mantra somewhere else, it is as good as to chant the Hare Krsna mantra in the temple. Your chanting may not be stopped; it does not matter where you chant.
Letter to Revatinandana, 13 June, 1970