You want to switch from Pepper to another lender - presumably for a lower interest rate.
Buy to let rates for Irish resident investors are very high, so there would be no point in switching.
They would also be capital and interest, so your repayments would be much higher - I am assuming you are interest-only at present.
So, in 7 years, you are going to need to refinance these loans. I think it will be very difficult for a non-resident to get such a loan, so you will be forced to sell.
If one of them is empty now, I would think it would be a good plan to sell it while you can. You don't want Pepper to appoint a Receiver in 7 years when you can't sell and you can't refinance.
SF has proposed that landlords who want to sell would have to sell with the tenants in situ. That would knock the value of your property by around 20%. I doubt that will happen, but it might and I would not take the chance. If your tenants leave, either property, sell it.