I can think of two possible routes that would fulfil this criteria in different ways.
The first is to get an IT job at a government organisation that isn't heavily IT focussed, but needs someone on staff "just in case". I once interviewed for a job at a National Library for a 35,000 GBP/year role (with 20% pension). They had a system where someone could book a room to read old manuscripts, and there was a C# program that let people swipe in and out with a smart card. For some reason they needed a dev on staff full time just in case anything went wrong. That was the whole scope of the job. Apparently most of the IT people there had other personal gigs they worked on most of the day, and it was super flexible. I didn't take it because I wanted a job that would push me and force me to learn things, but I reckon there would be a few jobs like that in government that would give you what you want.
The other way isn't exactly what you asked for, but might appeal to you anyway. Recently I've been working as a software contractor, mostly doing 3-to-6 month contracts, mostly for companies that need extra resource to hit some looming deadline. It's intensive work for the duration of the contract, but the money is a lot better than being a permanent employee, and I've been finding that over the course of each contract you can save up so much money that you could happily take a few months off in-between roles if you wanted to do what you like. I'm using the time off (just starting what I envisage to be a 4 month break minimum) to try to build side projects, but you could spend 4-5 months playing sport or whatever just as easily. You might even find the contract route gives you the time to do your hobbies, and professional fulfilment too, because each is timeboxed into several month long stints. Personally I love it.
I feel like I wouldn't be able to find good contracts but it might be imposter syndrome?
MSFT employee, most of what I need saved up but could use a bit more. I'd love to quit and just do some seasonal work but I imagine competition for the contracts you're talking about is pretty stiff and I don't have a huge professional network
You're in a fantastic company for networking, and Microsoft is a great partner for many small dev shops. Being a more niche Microsoft partner might be a good differentiator based on the Microsoft name on your resume.
The first is to get an IT job at a government organisation that isn't heavily IT focussed, but needs someone on staff "just in case". I once interviewed for a job at a National Library for a 35,000 GBP/year role (with 20% pension). They had a system where someone could book a room to read old manuscripts, and there was a C# program that let people swipe in and out with a smart card. For some reason they needed a dev on staff full time just in case anything went wrong. That was the whole scope of the job. Apparently most of the IT people there had other personal gigs they worked on most of the day, and it was super flexible. I didn't take it because I wanted a job that would push me and force me to learn things, but I reckon there would be a few jobs like that in government that would give you what you want.
The other way isn't exactly what you asked for, but might appeal to you anyway. Recently I've been working as a software contractor, mostly doing 3-to-6 month contracts, mostly for companies that need extra resource to hit some looming deadline. It's intensive work for the duration of the contract, but the money is a lot better than being a permanent employee, and I've been finding that over the course of each contract you can save up so much money that you could happily take a few months off in-between roles if you wanted to do what you like. I'm using the time off (just starting what I envisage to be a 4 month break minimum) to try to build side projects, but you could spend 4-5 months playing sport or whatever just as easily. You might even find the contract route gives you the time to do your hobbies, and professional fulfilment too, because each is timeboxed into several month long stints. Personally I love it.