SQL Server 2008 R2 upgrade to 2017
As always it depends... 

Whats the complexity of your instance?
How many SSIS packages / SSRS reports do you need to move along?
How much time do you have to perform this upgrade?
Whats your maintenance windows within which the service can be inaccessible?
And many many more...

Before you start looking for any kind of answers I would recommend to create an inventory of what exactly do you have.
Very helpful thing is to add source control over your entire DB server. With that in hand you can "mask it a bit" and then share with the community - much higher chances for good answers.