OK then yup, that area where the hotels are is the closest to the airport you could go with your trailer. Go like you're going to the airport (whichever way you choose to get there, be aware E-470 is a toll road that charges by number of axles, but it is the fastest/easiest way). If you are already on Pena, you can get off at Tower Rd and just head south, lots of places around there to stop off. Then you can get back on Pena and head south to get on I-70.
If you want something that's a little more on your way, then there is a large shopping center off Highway 7 and I-25. There's a Sears, Costco, Starbucks and some restaurants and some other stores with plenty of parking. Those aren't as close to the airport, it'll probably be around $40 for your friends to do an Uber/Lyft, but it's more convenient for you since you won't have to keep going east. I live a bit east of there and it's about $35 to DIA from our house with Lyft. Then, you can get back on I-25, then get on 76 to get across to I-70, avoiding the worst part of I-70 through Denver that is congested and under construction.
2020 Keystone Montana High Country 294RL
2017 Ford F350 DRW King Ranch
2021 Ford F350 SRW Lariat Tremor
