You will have enough time. Last summer flying in Europe was very interesting and I misconnected everywhere. I suspect it will be much better this year.

Also, I flew back through IAD and had enough time to enjoy the Polaris Lounge there before my connection. Enjoy! Also, I loved my time in EDI. Enjoy that as well.

We are definitely flying IAD - FRA - EDI, spending about 4 days there and then gonna take the last 2-3 days somewhere else. Deciding between DUB or ZRH right now but seeing what else is out there. May use excursionist perk to get the flight from EDI to ZRH on Edelweiss for free but not sure yet as if I booked this all through United I would be short by about 30k miles

Visited Scotland in 2021 and decided to fly into London and then connect to BA on a separate ticket. It made more sense with the covid restrictions at the time and didn't take us as far out of the way as Frankfurt, an airport I loathe. The nonstop UA flight was not operating at the time.

I bought a ticket in business on BA to get access to the lounge at LHR, and they served a three course meal on the short flight that was better than UA transcon first meals.

Anyway, if I were you I would take the nonstop IAD-EDI flight and avoid connections all together. Why not do that? Yes, it's on a 752, but it's such a short flight anyway. And even if you're thinking the seat will be better on a widebody, connecting through FRA, you're going to add hours of connecting time (including stress and one or two of those 100 mile bus rides they love at that airport) and sitting in an economy sized seat on the hop to EDI. Connecting in FRA will add probably five hours to what would otherwise be a seven hour trip.

I think United only flies EWR - EDI.... If we flew IAD - LHR we would still need a connection to EDI or train from London. Flight would be at least 2 hours once you take into account connection and train is roughly 4-5 hours. So we figured if you connect in FRA, get lounge access there and still get to EDI at roughly 11;30am local time

Seasonal flights between IAD and EDI start in early May.

Probably shouldve mentioned we are looking for mid to end of Feb

Ah, well I would probably do EWR if it were me. One security screening instead of two, 1-2 likely bus gates avoided in FRA. Also avoids LH customer service, which has not been super helpful in my experience when things go wrong, and their agents' often officious approach to cabin baggage.

Yes, but the Senator lounges are a bit better. If *Gold then you can use the Senator lounges.

A bit better and less crowded

I wish I was *Gold. Only status I currently hold is Gold on AA

I would not worry too much about Business lounge only. I've found the food spread to be much the same and the seating similar, if a tad more crowded (which both are likely to be mid-morning). I wouldn't alter plans over it.

The lines for passport control in Frankfurt can be horrendous. One data point - last April we flew EWR-FRA-ARN on Lufthansa and the line for non-EU citizens was about 100 metres and completely still. Luckily we are EU citizens and passed through in a couple of minutes (with jealous eyes from the people in the line). It seems you have a good amount of connection time, but be prepared for a potential long wait in line. Once you pass through, though, even the business class Lufthansa lounges are a nice place to spend time.