I think the big question would be, why would you consider upgrading your CMS and still use an unmaintained framework for your web application?
DD4T 2.0 is the current and maintained release, there is full support in there for using the Web 8 CIL (https://github.com/dd4t/DD4T.Providers.SDLWeb8.CIL),.
However you should be able to use DD4T 1.31 with the Web 8 in process API, and even the CIL, since they are backwards compatible. YouThere are no Web 8 providers built for DD4T 1.31, since it is not maintained anymore. But you can simply do thatuse the Web 8 Content Delivery stack by updating the assembly bindings in your web.config
like I described in my article about using DXA 1.2 with Web 8 (please. Please note DXA is using the DD4T provider (be it the 2.0 version), hence the similarities, although you might need to do some additional steps for DD4T specificly).