yes, you will have to recreated your services. If you were already on 10.1 or above you could upgrade them....but see the other links re: migration from 10.0. Just start with 10.4.1 as a new install and created them....don't bother with the others at this point.
ArcGIS for Server is a 64-bit application and requires a 64-bit operating system. If you are currently using a 32-bit operating system, you'll need to upgrade to a 64-bit operating system before you can install ArcGIS for Server.
If you are unsure whether or not your operating system is supported with ArcGIS for Server, see the system requirements.
You should have a directory with all the mxd's used for publishing but if not you should go to C:\arcgisserver\directories\arcgissystem\arcgisinput and get all the MXD's. For example C:\arcgisserver\directories\arcgissystem\arcgisinput\SERVICE1.MapServer\extracted\v101\service1.mxd
Put them in some temporary directory and republish them after a clean install.
If you change any parameters (for example number of instances) you will have to remember it.
You can get the model/python scripts in the same way for GpServices (even they usually a little different then original).
Image services you just have to check where the original image/mosaic is and republish.
A little work but not too much.