I've been busy on the computer myself during the dark evenings and spent a couple of them last week selecting all my rides on Veloviewer so that they all have had their definitive tiles calculated. Approx 900 rides altogether but left out my commutes (approx 600) as they are mostly less than 15km and I will have ridden the same areas on my longer rides anyway, this left about 300 rides in total.
Before I started
Total Tiles 3173, Max Cluster 1236, Max Square 30 x 30
Occasionally I would gain a tile but the general trend was downwards (I'd check my summary every so often)
After getting the definitive tile list for all the rides my stats were
Total Tiles 3163, Max Cluster 1207, Max Square 23 x 23
I'd lost 3 squares from within my original max square, when I looked closely it was clear that I hadn't actually entered these squares. No big deal as they're all relatively close (within a 65km round trip).
After a couple of rides I'm back to
Total Tiles 3179, Max Cluster 1256, Max Square 26 x 26