You might be fine on a short ride like that but I know I really started to struggle to keep up with friends on the latter part of 3 to 5 hour rides when I was restricting calories (but not as drastically as 1,000 cals under!) I upped the calories and could really feel a difference.
Personally, I would agree with the others. Don't go so aggressive. I tend to think, be it physiological or psychological, the quick it comes off, the quicker it can go back on.
I'm not sticking to -1000 religiously and if I was going out on a big all day ride I'd eat accordingly. It's more about my weekdays. Weekends I manage just fine really. Really it's between 750-1kg I'd like to lose each week until I'm down to 85 and then I'll take things at a better pace
I appreciate what I'm doing may not be for everyone and I may struggle but it's just how my mind works. In for a penny, in for a pound. No such thing as half a pregnancy etc.