Does it take considerably longer if you are picking up your own bags? We are flying in at night so I don't want them to pick up our bags for us.
How long you have to wait for your bags very much depends on how efficient your airline is at unloading & where your bags are in the unloading (hate it when my bags are one of the last to emerge on the carousel!) so add 15+ min.s plus for that.
Frontier uses the A terminal so add 5-10 minutes to schlepp your bags over to the B terminal where DME is.
Now you may immediately board a bus or what a short bit. There are always buses there and they direct you to a bus going to your resort - the buses leave all the time, so it’s not like just missing a park bus @ WDW, there’s no set schedule, they put you on a waiting bus and when enough people are on it they go.
Once you’ve been directed to a bus & stowed your bags underneath you may wait awhile for more people to get on the bus or you could leave right away. Assume 20 minutes here.
Once you arrive at WDW the real wild card enters the equation - how many resorts are they stopping at and will yours be the first or last stop. I’ve been first and I’ve been last, the worst was last after 7 stops. Usually it’s 3 or 4 stops. Plus how
long does the bus have to stop to unload people at each resort. One ride I remember a stop at one of the all stars where this family had a gazillion pieces of luggage and strollers and what not to be unloaded out from under the bus - plus, oblivious to the rest of us patiently waiting on the bus they delayed the driver even more w/ a lengthy conversation. If everyone has several bags to be unloaded and you’re the last stop it can be a long time on the DME bus.
Personally I love the luggage delivery service, nothing better than not having to hoist my big bag off the luggage carousel, wheel it through the airport w/ carryon, purse, etc., dropping my carryon in my room and going to that first park then returning to find the bags waiting in the room.