It is feasible, but the calculator shows £203,000 at 5.11% over 8 years as being £2,581 per month, which is a large amount.
If OP's husband is telling her they can pay it off at a lower amount in the same period, then he's either being mislead or he's misleading.
OP - The other thing I didn't mention is that if it transpires you've had bad deals because of your husband's (or your) lack of understanding, you may have a case for being mis-sold a product.
I remember years ago, when I was young and naïve, a mortgage broker (not independent, again in hindsight) convinced me and my ex to get an interest only mortgage with a separate endowment policy to cover the capital element.
It was all the rage back in the mid-90's, and they'd sold it to us on the basis that it was pretty much guaranteed that our endowment policy would end up way more than the capital element, so we'd actually be much better off.
A quick google will tell you how that ended up...
I never sought any compensation from the mis-selling because a) we only had the mortgage a couple of years and won't really have been massively financially disadvantaged; and b) it would probably mean having to contact me ex as we'd have to share any compensation - not appealing!