VL,
For what it's worth, my opinion would be to concentrate on longer flights.
If you can afford 3 hour per month, bear in mind that during the winter you probably won't fly as much.
If I was you, this would be my plan.
Winter months, plan two or thre local trips of one hour duration per month.
You'll porbably only get to fly one of them 1.
That's a fair saving, which you can allocate to the summer months
During the summer then once per month, do one trip to a destination that is 1.5 hours flying away. That's 3 hours return. Do a second local trip each month of just 1 hour round trip.
That's two trips per month during the summer totaling 4 hours, but you've saved some of that time from the winter period. The longer trips opens up lots of interesting places to go. I don't know what your access to an aircraft is like, but if you have the opportunity to keep the aircraft to 24 - 36 hours, then make the longer trip an overnight trip. It's a great way of seeing new places (not just the airfield cafe). It makes the flying much more enjoyable, and it's easier to justify the cost
If you're not allowed keep the aircraft for a weekend, then perhaps taking the last slot on a Saturday evening, and having it back by midday on Sunday may be acceptable?