Setting off on a marathon WIP

I have a new WIP. A HUGE WIP. A VERY VERY LONG TERM WIP. I bought a magazine containing the pattern for a lovely big blanket called 'Leafy Heirloom' by Kim Hargreaves a long time ago, and have been gazing at it ever since. Ravellers go here for the knit along. January sales fever got the better of me and I scoured the internet to find the required (vast) amounts of Rowan All Seasons Cotton for a good price.

With some kind of wonky logic I have decided that the best way to stop myself casting on more and more projects is to add this blanket to my list of WIPS. I like the excitement of casting on a new thing too much, and start to crave it way before I've finished the previous thing. The more I do it, the more WIPs I have, and the slower they all seem to progress, which makes me bored and itching to go for yet another something new. Vicious circle.

But here comes leafy heirloom to the rescue! To complete the blanket I need to knit 48 squares corner to corner then sew them together. I've done 4 so far, pictured above after I blocked them and sewed them together. Every time I feel a bit of mid-WIP itch on the other projects, I'll bang out another heirloom square to give me a bit of a change but not a whole-new-project-sized break.

Does that make sense, or am I just trying to justify a big splurge on a LOT of NICE yarn?!? It was more or less half price at Cucumber Patch and a very good deal (although 36 balls of anything is never going to be cheap!), so I've almost got myself convinced it's justifiable :)