Doesn't seem implausible to me: NDP can't vote for Grit budgets forever. However I'd think fall or perhaps early next year more likely.
The ONDP naturally cannot vote for Grit budgets "forever" - so far they have voted for exactly ONE - one year ago. But I suspect that unless Kathleen Wynne inserts some sort of a poison pill in the budget because she actually wants to engineer her own defeat - and I doubt that - the budget will probably be something the NDP can at least tolerate. No one wants an election now, all the parties are broke. If you're the NDP why not abstain, concentrate on winning the Windsor-Tecumseth and London West byelections and then look to an election another year down the road?