#Bike Time Trial
Skip the weather, use a training device. Doesn't matter if it's old or new, roller or fluid, so long as it works. Any trainer will work.
You'll need a speed meter and a timer. Cadence meters are very useful and can also make this task more interesting.
If you don't have a cadence meter, or you don't want to buy one, use an online calculator tuned with your bike measurements against the speed graph. This will give you a rough speed/cadence table to work with.
The trial is to match cadence with duration for repetitions. You will allow you to get some good milage in while keeping yourself preoccupied from thinking about distance.
The idea is simply to ride for as long as you set the timer. You do not stop until the timer tells you to. Give yourself no excuses, no stopping.
Ride 5 minutes at 50/rpm. Rest. Then again for 6 minutes at 60/rpm. Continue the pattern, while taking rest durations matching the previous repetition. The finish should be riding for 9 minutes at 90/rpm, resting for 8 minutes, and then riding 10 minutes at 100/rpm.
Do as many trials as you see fit.
It is more important to stay at the same cadence then it is to be fast. Given you're riding for 80/rpm, 79 is better than 85.
If the trial is too easy, increase the cadence or duration by 10%. Another option, if your trainer supports it, is to increase the resistance by 10%.
If the trial is too hard, decrease the cadence or duration by 10%.