Hi barry
It's not possible to predict which bank will be cheapest in the medium to longer term. If you open a Prestige Account, Danske is relatively cheap at the moment. Don't they have cheapish low loan to value mortgages as well?
So you should start with them. They might let you keep the cheap tracker or they might raise the margin on it from 0.5% to 1.5%. But, of course, they might refuse outright.
The cost of losing your tracker this year would be around 3% of €75k or about €2,200. It will reduce even further as you continue to pay down the loan.
Well worth trying to keep, but losing it won't make your mortgage unaffordable.
Brendan