You 100% will need to isolate if going via Amsterdam the government also made it clear yesterday they have started checking people are isolating. They have the ability to check 10k a day apparently. As you have 2 separate flights how long have you left between them.
It’s only a 3 night trip, Fri-Mon
I know you can do the test to release after 5 days and I do work from home, but it’s not ideal! Plus there’s the extra expense of an additional PCR test.
I might concede defeat and just stay in Blighty