I'm firmly in the "is" camp here. It seems to me that the core sentence is "there is a variety".

This is a tricky one in English, on the same model as "a group of items" or "a number of people", where either singular or plural may be used, depending on whether the emphasis is on the set as a whole or its elements. In this case, it is the variety that is wide rather than the holidays, and so the singular seems more appropriate to me.

Yep, put me down for 'singular', too. I think it should agree with 'variety'.

Thank you for your comment.

The singular sounds more natural here, when used to refer to different types of the same thing. The focus here is on "variety" not on holidays", so "There is ..." is absolutely fine. This can, of course, be used in plural form: different varieties of dishes. More explanations here: http://www.oxfordlearnersdictionaries.com/definition/english/variety_1 Hope that helps.