You can run a solid time even if the pack outmatches your current capability or if you fall off the pack regardless. Aim for a conservative, realistic goal for the 5K, then come through the mile faster than goal pace. Even if you spend most of the time in no-man's land running alone, the quick first mile should make up for the lack of competition.
For example, my goal was to break 16 indoors and I was aware the competition was likely to level me. Since sub 16 requires about a 5:08, I went through the mile in 5:01 and spent the next 2 miles running mostly alone. I ended up with 15:55 which averages to 5:07 per mile.
If the pack matches your goal ability, you should be able to run with them and keep a faster pace with sustained competition.
Remember to keep a constant focus on pushing the pace. If you feel comfortable, you are probably slowing down. Use clocks or watches to your advantage.