I think it must be allowed if you cannot fit all the parish into one Vigil. In my parish of over 6000, but whose church only seats about 350, we had 3 Easter vigils - one at 7.30p.m. and one at 10p.m in the church, as well as one at 6p.m. at the local convent. The first one was in another language (we are a very, very, very, very diverse parish, with huge groups of immigrants.) Last year, we had a fourth vigil at a different chapel, but this was not possible this year.
(And for those wondering why our church is so small - when it was built 150 years ago, just after Catholics were allowed to entrance to our country again, the entire parish could fit in the first couple of pews. They were in fact very forward-thinking in their building.)