Has anyone insured their garage outside house boundary to rent out?

[Garagrent]

COL crisis and all that... posting on legal too.

A close relative wants to rent out her unused garage which is on a separate plot of land to her house (outside the boundary although she owns the land it's on).
There are plenty of people willing to rent it, but she's struggling to get insurance and discovered her current home insurance hasn't covered the garage at all because it's separate to the house boundary.

Has anyone done this or have any advice? We think the best way would be to cancel her current policy and take out a new one which covers the garage - presumably telling them it's going to be rented out for storage - but which companies might do that?

Thanks for any help!

A good broker should be able to find cover but it's probably not the sort of business the comparison sites would find easy to place.

Thanks, no, definitely no good looking at comparison sites. And trying on a bank holiday Friday isn't the best idea either!