Nice to Maubec France (one day w/ Stop in Gorges du Verdon))

I think you may be too early for the lavender bloom around Valensole. The "Lavender Fields of Provence webpage" includes this guidance: "In the Luberon and the Rhone Valley lavender begins to bloom mid June. The Valensole plateau and Drome Provencal begins around the beginning of July. The area of Sault begins blooming mid July."

I believe your best bet is to head for fields at the lowest elevation possible. I'm afraid I can't provide any guidance on that, though the above statement hints that the Luberon or Rhone Valley may work if you are traveling late in June.

Perhaps someone here can give you a website to check for absolutely up-to-the-minute information so you don't go out of your way to see lavender plants not yet in bloom.

I trust that you are making only refundable bookings.

As acraven noted, check your time of the month. That is early for the Valensole, but you may have some viewing as you descend into the valley and head to Maubec. This is doable but the driving is slower than you might expect, especially since it is so scenic. With lunch and the canoeing, you should likely plan on heading straight on. You'll be passing quite a number of places, so unless you are going to loop back, stop instead at Gordes and the Abbey or simply along the valley floor along D900. Make sure you secure your stuff appropriately in the touristy areas, even in the countryside.