Just my tuppence.... in Germany, VFR flights are forbidden when the clouds are under 500 feet so in uncontrolled airspace, I would take that as my minimum to be able to start and land VFR - whether I would want to, is another topic. When viewing controlled airspace, Delta CTRs have minimum cloud bases of 1500 feet for VFR flight so there's your answer for that.
When departing you would likely also have to remain VFR until you exceed the Minimum Radar Vectoring Altitude which
AFAIK is 1000 feet above the highest object within 8km plus a 500 feet puffer for uncontrolled airspace so if the MRVA is (e.g.) 3000 feet, you wouldn't be allowed to do your trip....
On cancelling IFR, you'd probably be in Echo airspace which means you would need vertical separation of at least 1000 feet from clouds so again, you wouldn't be able to drop down to land...
On top of this, I shouldn't forget the minimum VFR altitude clearances - means 500 feet above the highest obstacle within 2000 feet radius when over clear ground or open water, 1000 feet above built up areas, except when coming in to land; however, I seriously doubt that a 10 mile final would qualify as a reason to be at 800 feet over a major city.....