Being a tax resident in germany is complex and usually required an accountant to help so i'd try to keep yourself living in the uk for tax purposes as possible.
When you normally rent in germany you need to prove you're a resident/register at a police station so hard to pretend you're still living in the uk unless you use airbnb long term.
To still be a uk resident you need to spend half the year in the uk (flying days can count for which every country you choose i think)
You still have to pay tax over a certain amount from money paid by lodgers, so probably still will have to show it on self-assessment.
https://www.gov.uk/rent-room-in-your-home/the-rent-a-room-scheme
Being a tax resident in germany is complex and usually required an accountant to help so i'd try to keep yourself living in the uk for tax purposes as possible.
When you normally rent in germany you need to prove you're a resident/register at a police station so hard to pretend you're still living in the uk unless you use airbnb long term.
To still be a uk resident you need to spend half the year in the uk (flying days can count for which every country you choose i think)