You will need to find a EU data plan(s) that makes sense for you given the countries. Do some searches. Lots of questions about data plans have been asked in the past on EF.
Since it will be on all day and lots of usage, you will need to look at options for charging/recharging the Huawei while you are driving. You could look at car charging (make sure about the requirements !) or you could use a 10'000 battery pack/power bank to do the same thing.
I know Swisscom has such a device, if not an unlimited european data plan is good. Maybe don't contract it in Switzlerland but abroad, it might be much cheaper.