SQL aggregating a text field based on latest date text value - string

Question

I have the following script:
DROP TABLE IF EXISTS [dbo].[test]
CREATE TABLE [dbo].[test]
(
[Name] [varchar](50) NULL,
[Amount] [int] NULL
)
GO
INSERT INTO [dbo].[test]
(
[Name]
,[Amount]
)
VALUES
('Abc - 20 april to 7 june 2020',25)
,('Abc - 20 april to 7 june 2020',33)
,('Abc - 20 april to 29 june 2020',15)
,('Abc - 20 april to 29 june 2020',55)
,('Abc - 20 april to 10 may 2020',20)
,('Abc - 20 april to 10 may 2020',75)
,('Abc - 20 april to 10 may 2020',89)
GO
SELECT *
FROM [dbo].[test]
The resulting table gives the following results:
Name | Amount
-------------------------------|-------
Abc - 20 april to 7 june 2020 | 25
Abc - 20 april to 7 june 2020 | 33
Abc - 20 april to 29 june 2020 | 15
Abc - 20 april to 29 june 2020 | 55
Abc - 20 april to 10 may 2020 | 20
Abc - 20 april to 10 may 2020 | 75
Abc - 20 april to 10 may 2020 | 89
I would like to be able to determine the most recent end date in the text field and eliminate the repetitive data by grouping it showing the record with the latest end date and aggregating the amount. The result should be a single record with the following data:
Name | Amount
-------------------------------|-------
Abc - 20 april to 29 june 2020 | 312
I've played around with some group bys and text manipulation functions and this is as far as I got using the following code:
select (case when [Name] like '%-%'
then trim(left([Name], charindex('-', reverse([Name])) - 1))
else [Name]
end) as [Name]
,sum(Amount) as Amount
from [dbo].[test]
group by
(case when [Name] like '%-%'
then trim(left([Name], charindex('-', reverse([Name])) - 1))
else [Name]
end)
The above code doesn't really do so much as to just aggregate unique records only. I was looking for something more intelligent that will find and recognize that all of my records really mean the same thing and that the latest end date in the Name field is 29 june 2020 and will only display that single record with the total aggregated Amount.
Any help would be much appreciated.