I have an older house too... a greek revival farm house built in 1900 (as in the year 1900). Not super old... my girlfriends family's house was built in 1785 I think. Super old but nice.
Our house has gone thru some major renovations most of which was done by the previous owner. Back in the late '90s. He used a lot of reclaimed materials which is super cool but there are areas that have drafts and let the hot in and the cool in too!
But you can't beat the character. We just had a custom front door made (odd dimensions and a radius top) we mimicked the exact door that was there previously. Even reused the glass that was on the old door. The millworker was like, "you know this is going to let the cold in during the winter time?". I was like "yup".
Not to get off topic but here is a pic of that door.... the millworker is a super job and nailed the original even down to ordering a special router bit for the molding. He didn't charge me for the router bit he had to buy because he said the detail was so freaking unique he was going to use it on his other projects.
Old door:
New door:
Sometimes you just have to go with whats right and not what everyone else is doing....